APPENDIX 3
ACT VOCABULARY
LIST
All of these words have been used on past ACTs. Some of them are included
because former students asked about them. Some are included here because
they have been selected by experienced ACT instructors as representative of the
vocabulary level that is expected on the ACT. We have also included some math
and science terms with which you should be familiar.
A
Abound:
to be well supplied; to have great quantities
Absence:
being away or lacking something; inattentiveness
Absurd:
extremely ridiculous or completely lacking reason
Abundance:
having considerably more than is necessary or adequate; more than
plenty
Acceleration:
the rate of change of velocity
Accommodate:
to adapt or adjust in a way that makes someone else comfortable; to
make room
Accusation:
a statement blaming someone for a crime or error
Acidic:
having a pH less than 7 (contrast with alkalinity, which is having
a pH greater than 7)
Acrid:
harsh or bitter taste or smell
Acute:
(adj.) refers to an angle that is less than 90 degrees; (adj.) refers to
a triangle with angles that are all less than 90 degrees; sharp; quick
and precise; intense
Adapt:
to change or modify to suit a particular purpose
Adjacent:
in the nearest position; next to
Adolescence:
the stage of development between puberty and maturity
Aerobic respiration:
the breakdown of glucose in the body of an animal to supply muscles
with oxygen
Aerosol:
solid or liquid particles suspended in gas
Aesthetic:
appeals to the senses because it is beautiful
Affiliation:
a connection between groups of people, organizations, or
establishments
Agility:
the quality of being quick and nimble
533
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APPENDIX 3
Agronomist:
a soil management and field-crop production expert
Alienate:
to isolate oneself from others or another person from oneself
Align:
to adjust parts so that they fit together correctly, usually in a straight
line
Alkalinity:
having a pH greater than 7 (contrast with acidic, which is having a
pH less than 7)
Allegiance:
loyalty to a person, group, country, or cause
Altitude:
elevation above a level of reference, usually given in feet above sea
level
Ambiguous:
unclear or capable of having more than one meaning
Amino acids:
various organic compounds that link together to form proteins
Ample:
a more-than-sufficient amount; roomy
Analogous:
items that are similar and comparable in some way; serving a
similar function
Analogy:
a comparison of similarities between two or more things
Anatomical:
related to the structure of an organism
Ancestral:
relating to or inherited from an ancestor
Anew:
starting again in a new or different way
Anomaly:
something that is different from the norm
Anticipate:
to look forward to or to expect
Antigen:
a substance such as a toxin or enzyme capable of eliciting an
immune response
Antitoxin:
an antibody created for and capable of neutralizing a toxin
Apathy:
lack of any emotion or concern
Aperture:
an opening or hole, usually in an optical instrument, such as a
camera, that limits the amount of light passing through a lens
Apocalypse:
great or total devastation; approximating the end of the world
Apparatus:
a material or device used for a specific purpose
Appealing:
attractive or inviting; the act of making a request for a decision
or help
Arisen:
the state of being up after sitting or lying
Aristocratic:
having the qualities of the elite, ruling class
Articulate:
(v.) to clearly explain; (adj.) the quality of being able to speak clearly
Aspect:
a certain part of something; the side of an object that faces a certain
direction
Assert:
to demonstrate power; to defend a statement as true
Assumption:
something believed to be true without proof; unsupported evidence
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Asteroid:
small celestial body that revolves around the sun, with a diameter
between a few and several hundred kilometers
Asthenosphere:
a lower layer of the Earth’s crust
Astonishing:
amazing or bewildering
Atrium:
an area of a building, usually a courtyard, that is skylighted or open
to the sky and that often contains plants
B
Bacteria:
single-celled microorganisms
Banish:
to force to leave; to exile
Banyan:
East Indian tree that has aerial shoots growing down into the soil
and forming additional trunks; loose jacket worn in India
Basalt:
solidified lava; a dense, gray, fine-grained igneous rock
Bemoan:
to express grief; to deplore
Beneficiary:
recipient of benefits, for example, funds or property from an
insurance policy or will
Binge:
a duration of excessive and uncontrolled self-indulgence
Biomass:
total mass of all the living matter within a given area
Biosynthesis:
the production of a chemical compound within the body
Boiling point:
the temperature a liquid must be to change states from liquid to gas
Brood:
(v.) to dwell over past misfortune; (n.) a group of offspring
Buoyant:
tending to float; lighthearted
Bureaucrat:
an official in government; a term usually used in an insulting
manner
By-products:
products made in the process of making something else, sometimes
unexpected
C
Calamity:
horrible event that results in extreme loss
Calligraphy:
elegant lettering; the art of producing such writing
Capacity:
maximum amount that an object or area can hold; mental ability
Capillary:
a very slim tube; one of a network of extremely small blood vessels
Carbohydrate:
sugars and starches that serve as a major energy source for animals
Catalogue:
a systematic list of things, such as books in a library or items for
sale at a store
Catalyst:
an agent that causes or speeds up a chemical reaction
Celestial:
relating to the sky; divine or heavenly
536
APPENDIX 3
Celsius:
a temperature scale in which the freezing point of water is 0 degrees
and the boiling point is 100 degrees under normal atmospheric
conditions
Cerebral edema:
brain swelling
Cesarean:
relating to the medical procedure of surgical abdominal birth,
referred to as a cesarean section
Chaos:
a state of complete disarray
Characteristics:
distinguishing attributes or qualities of a person or thing
Chlorophyll:
a green pigment produced in response to sunlight during photosynthesis
Cholesterol:
a soft, waxy compound found in the body and in the food we eat
Chronology:
a list of events arranged by time of occurrence
Circumscribe:
to enclose a shape with lines or curves, so that every vertex of the
enclosed object touches part of the enclosing configuration
Coherent:
the quality of being logical and clear
Cohesiveness:
the quality of sticking together
Coincidental:
occurring by chance
Collinear:
passing through or lying on the same straight line
Colloid:
a gelatinous material
Comet:
a celestial body, having an elongated, curved vapor tail, which is
seen only in that part of its orbit that is relatively close to the sun
Commendable:
worthy of praise
Common difference:
the equal distance between one number in an arithmetic sequence
and the next (for example, the common difference between 4, 6, and
8 is 2.)
Common ratio:
Comparison:
the ratio of one term and the next in a geometric sequence
4
8
(for example, the common ratio between 2, 4, and 8 is and , or 2.)
2
4
a description of similarities or differences between two things
Compatriot:
someone from one’s own country; a colleague
Competence:
the quality of having adequate skill, knowledge, and experience
Compose:
to form by placing parts or elements together; to bring oneself to
a state of calm
Comprehensive:
all-inclusive
Compressibility:
the ease with which pressure can alter the volume of matter
Concede:
to admit or reluctantly yield; to surrender
Concentration:
the amount of one substance contained within another; intense
mental effort or focus
Concentric:
having a common center
A C T V O C A B U L A RY L I S T
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Concerto:
composition for an orchestra and one or more solo instruments,
typically in three movements
Concoct:
to prepare by mixing ingredients together; devise a plan
Condense:
to become more compact; to change from a vapor to a liquid
Conducive:
tending to cause or bring about
Congruent:
corresponding; equal in length or measure
Conjure:
to bring to mind; to produce as if by magic
Conscience:
the mental sense that guides moral decisions
Consecutive:
uninterrupted sequence
Consent:
(n.) permission; (v.) to agree to
Consequence:
result of an action
Conservatory:
a fine arts school; a greenhouse of plants aesthetically arranged
Constant:
the quality of being unchanging; marked by firm resolution or
loyalty
Constituency:
a group of citizens who have the power to elect an official; an
electoral district
Contemplate:
to carefully consider
Contemporary:
person or thing of the same era or age; current, modern
Context:
text or spoken words that surround a word or passage and help
determine meaning; circumstances that surround an event
Contradict:
to assert the opposite
Contrive:
to clearly plan; to cleverly devise
Controversial:
characterized by dispute; debatable
Cordial:
sincere; courteous
Correlate:
to have corresponding characteristics
Cos:
abbreviation of cosine
Cosine:
in a right triangle, the ratio of the length of the side adjacent to
adj
the acute angle divided by the hypotenuse (cos ¼
)
hyp
Credulity:
a tendency to trust too easily
Crimson:
a deep red color
Criterion:
requirement on which judgment can be based
Crucial:
extremely important
Cryopreservation:
preservation (as of cells) by very low temperatures
Cube:
a term raised to the third power; a regular solid having six congruent
faces
Cubic inch:
the volume of a cube with edges that all measure one inch
538
APPENDIX 3
Cuisine:
the food prepared by a style of cooking, for example, ‘‘Italian
cuisine’’
Cylindrical:
having the shape of a cylinder, or a solid with circular ends and
straight sides
D
Decipher:
to interpret the meaning, usually of a code or hard-to-read
handwriting
Decompose:
to disintegrate into components
De-emphasize:
to minimize the importance
Defection:
withdrawing one’s support; to escape or become a traitor
Deform:
to disfigure; to ruin the shape of an object
Degree:
one in a series of steps in a process or scale; a unit of measurement
Delegate:
(v.) to transfer responsibilities to another; (n.) a personal
representative
Deliberate:
(adj.) carefully planned out; (v.) to consider carefully
Delve:
to deeply and thoroughly search
Demean:
to reduce in worth
Demise:
the end of existence
Demur:
to express opposition
Derive:
to infer certain knowledge; to trace the origin or development of
something
Descend:
to come from a particular origin; to move down from a higher point
Descendant:
a person, animal, or plant that can be traced back to a certain origin;
future or subsequent generations
Deter:
to prevent from taking a particular course of action
Determinant:
the difference between multiplied terms in a matrix
Deviation:
a divergence from a certain path; in mathematics: the difference,
especially the absolute difference, between one number in a set and
the mean of the set
Devise:
(v.) to design or create; often confused with the noun device, which
means ‘‘tool that fulfills a certain purpose’’
Diagonal:
a line segment joining two nonadjacent vertices of a polygon or solid
(polyhedron)
Diffusion time:
the time that it takes for a material to spread from one area to
another
Diligent:
continuously putting in great effort
Dilute:
to weaken the strength of a solution
Diminish:
to make smaller, decrease, or lessen
A C T V O C A B U L A RY L I S T
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Directly proportional:
increasing or decreasing together or with the same ratio
Disavow:
to deny knowledge of, responsibility for, or association with
Discern:
to differentiate or distinguish; to perceive
Discomforting:
embarrassing
Disconcerting:
unsettling
Discriminatory:
showing a bias
Disdainful:
scornful and sneering
Dispel:
to rid one’s mind of; to drive out
Disperse:
to scatter or spread out everywhere
Disquieting:
lacking peace of mind; mental unrest
Dissolution:
the process of dissolving or disintegrating
Dissolve:
to pass into or and become part of; to terminate
Distinct:
easily distinguishable from others
Dominant:
the most prominent; exuding authority
Dowry:
in certain cultures, the money, goods, and so on, that a woman
brings to a marriage
Drag force:
the frictional force that resists or slows down motion through a
medium such as air
Drastic:
extreme
Durable:
resistant to wear
Durable goods:
in economics, goods that are not depleted with use, such as
household appliances or cars
E
Ecology:
the field of science that concentrates on relationships between
organisms and their environments
Elaborate:
(adj.) rich with detail and well developed; (v.) to expand on the idea
of something
Electorate:
the body of all of the people who possess the right to vote
Eloquent:
very clear and precise; quality of being skilled in clear and precise
speech
Emanant:
something such as a gas or odor coming forth and off of a source
Embalm:
to maintain a dead body by treating it with chemical preservatives
Embittered:
possessing bitter feelings
Embrace:
to enclose in one’s arms; become accepting of other ideas or people
Emigration:
leaving one country and traveling to live in another
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APPENDIX 3
Emissions:
things that are discharged (often gases into the air)
Emit:
to release particles such as light, heat, gases
Empowered:
possessing the necessary abilities for a particular task; given power
or authority
Emulate:
to follow an admirable example; imitate
Emulsion:
a state in which one liquid is suspended in another because the
liquids will not dissolve in one another
Endorsement:
a guarantee to support; a signature on a document such as a check
Endow:
to give a positive trait; to provide monetary funds by donation
Endpoints:
what defines the beginning and end-of-line segment
Endure:
to continue despite difficulty; to tolerate
Enrich:
to improve
Enshrine:
to enclose in a shrine or place of devotion
Entangle:
to twist and tie up in a complicated manner
Enumerate:
to state things in a list
Envision:
to picture a mental image
Eon:
duration of time, so long it cannot be measured
Epic:
(n.) widely celebrated literary work that has survived a long period
of time; (adj.) very impressive and extraordinary
Epicanthic fold:
a fold of skin of the upper eyelid that only partly covers the eye’s
inner corner
Equilibrium:
a state of balance
Erosion:
the wearing away of an object by outside forces, like wind or water
Error:
a mistake; the difference between a computed value and the correct
value
Escapist:
one who mentally leaves the real world for a world of fantasy
Essence:
important characteristics that help differentiate something; the key
element of an idea; something spiritual; a scent
Essential:
(adj.) the quality of being indispensable or necessary
Essentially:
at the very core
Establish:
to create a foundation
Ethical:
in line with what is right and wrong
Ethnicity:
cultural and racial association
Evaporate:
to draw away moisture and convert into vapor
Exceed:
to go far beyond a limit; excel
Exceptional:
rare due to uncommonly great qualities
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Exhibit:
(v.) to display; (n.) something that is displayed; (n.) a piece of
evidence submitted to a court during a trial
Expatriate:
(v.) to banish someone; (v.) to move from one’s native land; (n.) one
who lives in a foreign country
Experimental variables: elements of an experiment that are changed (distinguished from the
constant, which is held the same in order to produce significant
results)
Expertise:
skill or knowledge in a certain area
Exquisite:
characterized by great beauty and intricacy
Extensive:
detailed and far-reaching
Extinct:
no longer existing
Extrapolate:
to guess by inferring from known information
Extravagant:
lavish beyond the norm
Exultant:
gleeful because of success
F
Fahrenheit:
a temperature scale that measures the boiling point of water at
212 degrees and the freezing point at 32 degrees
Feign:
to fabricate or deceive
Fermentation:
the chemical process of breaking down an organic substance into
simpler substances such as the fermentation of sugar to alcohol
Fickle:
constantly changing one’s mind
Fjord:
an inlet lined by steep slopes that is long, narrow, and deep
Fledgling:
a young bird that has just acquired feathers; also used to describe an
inexperienced newcomer
Flourish:
(v.) to prosper; (v.) to thrive; (n.) a dramatic gesture; (n.) a written
embellishment
Foil:
(n.) a character whose traits exemplify the opposite traits of another
character when they are compared; (v.) to prevent an action, often
by ruining a plan; (n.) a weapon used in the sport of fencing
Foliation:
the alternating layers of different mineral compositions within solid
rocks
Forecast:
to predict future events, such as the weather
Foresee:
to know beforehand
Foreshadow:
to suggest or hint at future occurrences
Forgo:
to refrain from doing something previously planned
Formalize:
to make something official or valid
Franchise:
a right given to an individual or group to operate a branch of a
business and sell the business’ products; the right to vote
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APPENDIX 3
Frenzied:
in a temporary crazed state
Friction:
the force resistant to motion
Frivolous:
unnecessary and silly
G
Gable:
the triangular section of a wall that fills the space between the two
slopes of a roof
Galvanism:
a direct electrical current produced by chemical reactions
Gas:
a fluid (such as air) that is not independent in shape or volume but
tends to expand
Gas chromatograph:
a device used to detect the composition of an unknown material
Gastric emptying:
the movement from the stomach to the small intestine, and finally
into the colon
Gaudy:
tastelessly flashy
Glacial:
relating to a glacier; callous and cold; extremely slow
Glib:
doing something with ease and slickness, but lacking sincerity
Gravity:
the force of attraction between two bodies of mass
Gypsum:
a yellowish-white mineral used to make plaster
H
Haggle:
to bargain in an annoying manner; to harass
Halitosis:
the condition of having breath with a foul odor
Harbinger:
a sign that foreshadows upcoming events
Herbivorous:
a plant-eating organism
Hindu:
(adj.) relating to the religion of Hinduism, which originated in India;
(n.) a person who practices Hinduism
Hoist:
to lift up
Homeric epic:
a classic Greek tale of heroism written by the ninth-century Greek
author, Homer
Hue:
color
Humidity:
a measure of how damp the air is
Hydraulic:
operated by using water or fluid pressure
Hydrogen bonding:
the chemical bonding of a hydrogen atom with another electronegative atom
Hypotenuse:
the longest side of a right-angle triangle, which is always the side
opposite the right angle
A C T V O C A B U L A RY L I S T
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I
Ideological:
relating to the fundamental ideas of an individual or group
Idiosyncrasy:
a peculiar characteristic
Igneous rock:
rock that is formed by the cooling and solidification of molten
magma
Ignition temperature:
the temperature that a fuel must reach before combustion can begin
Immerse:
to completely submerge
Imminent:
close to happening; impending
Imply:
to indirectly suggest, often confused with infer, which means
‘‘to conclude’’
Improvise:
to do or perform without preparation; to create something only
from readily available materials.
Inalienable:
impossible to take away
Inauguration:
a formal initiation or induction
Incarcerate:
to imprison
Incinerate:
to set fire to and burn something until it is reduced to ashes
Inclined:
disposed to a certain path of thought; sloping
Inconstant:
not following a pattern; varying
Incorporate:
to bring two things or certain aspects of two things together
Indifference:
total lack of concern or interest
Indigenous:
native to or naturally existing in a certain area
Indignation:
anger due to unfairness
Indulge:
to freely partake in; to yield to the wish or desire of oneself or others
Inevitable:
bound to happen; unavoidable
Inexhaustible:
plentiful; impossible to use up completely
Inexplicable:
impossible to give the reason for; unexplainable
Infer:
to deduce from evidence, often confused with imply
Infirmary:
a small hospital, often in an institution, used to provide care for
the sick
Infrared:
light energy having a wavelength below the visible range; it is
experienced as heat
Infuse:
for one substance to penetrate into another (for example, steak
infused with garlic flavor)
Ingenious:
brilliant and clever
Inherent:
naturally occurring, permanent element or attribute
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APPENDIX 3
Inscribe:
to write or engrave words on a surface; to write one’s name on
something
Insinuate:
to subtly imply
Institute:
(v.) to enact or establish; (n.) an organization
Institution:
an establishment; a pillar of society (for example, the institution of
marriage)
Interior angle:
an angle inside of a shape (that is, all of the interior angles in a
triangle add up to 180 degrees)
Intern:
one who is confined during wartime against his or her will;
a student or recent graduate working as an apprentice in a certain
professional field
Interpret:
to translate or explain a concept
Interpretation:
a personal explanation for another’s creation, such as a play or
poem
Interstitial:
(n.) fluid outside of cells; (adj.) occupying the small spaces between
objects; (adj.) occurring during the short time periods between
events
Intracellular:
within a cell or cells
Intricacy:
a detail of something complex
Invaluable:
priceless
Involuntary:
an action done without one’s consent or free will
Irony:
use of words to express a meaning that is the opposite of the real
meaning; similar to and often confused with sarcasm, which means
‘‘words used to insult or scorn’’
Irreconcilable:
impossible to adjust or compromise
Irrelevant:
not relevant or pertinent; outside the scope of a discussion or
argument
Irrevocable:
impossible to reverse
Isosceles triangle:
a triangle with two congruent sides and two congruent angles
Isotopes:
two or more atoms with an identical atomic number and differing in
number of electrons
J
Juxtaposition:
an act of placing things next to each other, usually for comparing or
contrasting
K
Kelvin:
a unit of temperature where 0 K is absolute zero, the freezing point
of water is 273 K, and the boiling point of water is 373 K
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L
Languish:
to become weak; to become disenchanted
Lavish:
(adj.) elaborate and luxurious; (v.) to freely and boundlessly bestow
Law of Sines:
the relationship among the angles and the sides of a triangle (the
sine of the angles is equal to the lengths of the sides)
Least Common
Denominator (LCD):
the smallest number (other than 0) that is a multiple of a set of
1
1
denominators (for example, the LCD of and is 12)
4
6
the smallest number that is a multiple of a set of numbers (for
example, the LCM of 6 and 9 is 18)
Least Common
Multiple (LCM):
Liberally:
done in a manner that is generous (for example, liberally applying
sunscreen)
Limbo:
a precarious state; in Roman Catholicism, the otherworldly place
for unbaptized but good people
Linear:
relating to a line
Lipid:
an oily/waxy organic compound that cannot be dissolved in water
Liquid:
(n.) a substance that is neither a solid nor a gas; (adj.) flowing freely
Lithosphere:
the outer part of the Earth that includes the crust and upper mantle
Log:
abbreviation of logarithm. Logarithms are used to indicate exponents of certain numbers called bases. By definition, logab ¼ c if
ac ¼ b (for example, logx36 ¼ 2 if x2 ¼ 36. In this case, x ¼ 6.)
Lumbering:
lethargically walking around with clumsiness
M
Macrophages:
protective cells
Manifest:
(adj.) clearly recognizable; (v.) to make clear; (n.) a list of
transported goods or passengers used for record keeping
Manometer:
a device that measures the pressure of liquids and gases
Marine:
(adj.) relating to the sea; (n.) a member of the U.S. Marine Corps
Matrix:
rows and columns of elements arranged in a rectangle
Mean (also
arithmetic mean):
average; found by adding all the terms in a set and dividing by the
number of terms
Median:
the middle value in a set of ordered numbers
Mediocre:
lacking any special qualities, even inferior
Melancholy:
glumness; deep contemplative thought
Melting point:
the temperature at which a solid softens into a liquid
Mere:
small; (adv. merely) nothing more
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APPENDIX 3
Mesosphere:
a layer of the atmosphere fifty to eighty kilometers above the Earth’s
surface
Metamorphism:
the process of altering solid rock by changing its temperature,
pressure, and chemistry
Meteorite:
a meteor that reaches the surface of the Earth before it is entirely
vaporized
Meticulous:
devoting a high amount of attention to detail
Microorganism:
an organism of microscopic or very small size
Midpoint:
the point that divides a line segment into two equal segments
Minuscule:
extremely small; unimportant
Mole:
a unit of measurement for the molecular weight of a substance
Molecular weight:
the weight of all of the atoms in a molecule
Molten:
turned to liquid because of heat
Moral:
(adj.) based on standards of good and bad; (n.) a rule of proper behavior
Morale:
mental well-being; mood
Mortar:
a bowl in which substances are ground; a mixture, usually cement
and water, used to bond bricks or stones; a military weapon similar
to portable artillery
Mutability:
the ability to transform
N
Nanometer:
one billionth of a meter
Negligible:
meaningless and insignificant
Neural:
relating to the nervous system
Neurological:
relating to neurology, the study of the nervous system
Newton:
the amount of force needed to accelerate a one-kilogram mass at a
rate of one meter per second, per second
Nostalgia:
sentimental yearning for the past
Notion:
a belief, sometimes without much conviction
Numerous:
existing in great numbers of units or persons
O
Oblong:
deviating from a square, circular, or spherical form by being slightly
longer in one area
Obtuse:
an angle that is larger than a right angle
Offal:
wasted trimmings of an animal carcass; trash or rubbish
Onus:
a burden of responsibility
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Opus:
a creative composition, usually musical
Oracle:
a shrine devoted to a future-telling deity or the deity himself;
a prophet
Organic matter:
matter that is derived from living organisms
Organism:
a living thing, either plant or animal
Overt:
obvious and clearly shown
P
Paradox:
a statement that seems contradictory but is actually true
Paragon:
an example of excellence
Parallel:
lines in the same plane that do not intersect each other; in a
coordinate plane, noncollinear lines or segments having the same
slope as one another
Parallelogram:
a quadrilateral (a figure that has four sides) with opposite sides that
are parallel and congruent
Parenthetical:
an explanatory statement that is set off by parentheses
Pathetic:
deserves pity or sympathy
Peculiarity:
unusual quality or characteristic
Pendulum:
a device that is suspended in such a way to allow it to swing back
and forth using gravity
Perceive:
the act of becoming aware of something, usually through the senses
Percolate:
to slowly pass through a porous substance
Perfunctorily:
in a manner that suggests little interest or attention; a routine duty
Perimeter:
the boundary of a figure; in math, the distance from one point
around the figure to the same point
Periphery:
the outermost boundary of an area
Perpendicular:
lines that intersect and form 90-degree angles
pH:
a scale that measures how acidic or basic a substance is on a scale of
0 to 14. Lower numbers indicate an increasing acidity and higher
numbers indicate increasing basicity
Phantom:
exists only in the mind (an illusion); a ghost
Phenomenon:
an event or circumstance that is significant or extraordinary
Photophores:
organs that produce light
Photosynthesis:
the process by which plants turn carbon dioxide and water into
energy with the aid of sunlight
Pigmentation:
coloration
Plagiarism:
an act of fraud consisting of copying another’s work and pretending
that it is original
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APPENDIX 3
Positive slope:
(y1 y2 )
(x1 x2 )
the incline of a line that slants upward (from left to right)
Pow-wow:
a meeting or gathering
Preceding:
coming before
Precipitate:
to cause something to happen very suddenly
Precipitation:
falling products of condensation in the atmosphere (such as rain)
Predominant:
having superior strength, paramount
Preliminary:
precedes or comes prior to
Prerequisite:
required beforehand
Prestigious:
having honor or respect from others
Prevail:
to triumph or come out on top
Prevalent:
commonly used or occurring
Prime number:
a positive integer that can only be evenly divided by 1 and itself
Primordial:
happening first or very early
Protagonist:
the main character of a story or tale
Protein:
a compound that consists of amino acids and plays various
structural, mechanical, and nutritional roles within organisms
Prototype:
an original form of something
Protract:
to lengthen or prolong
Prowess:
great skill in something
Pseudoscience:
irrational or unfounded beliefs masquerading as science
(for example, astrology)
Psychologizing:
explaining something in psychological terms
Pyrotechnics:
a display of fireworks
Point-slope formula:
the formula used to calculate the slope of a line:
Q
Quadrant:
one part of a larger object that has been divided into four parts
Quadratic equation:
an equation in the form of ax2 þ bx þ c ¼ 0, where a 6¼ 0, and has only
two solutions for x
Quasi:
resembles to some degree
Quintessential:
considered the perfect form
R
Radian:
a unit of angle measure within a circle
Radiate:
to emit energy or light that extends from a single source
A C T V O C A B U L A RY L I S T
549
Radii:
the plural form of radius
Radioactive decay:
a natural process by which an atom of a radioactive isotope
spontaneously decays into another element
Radius:
a line segment with endpoints at the center of the circle and on the
perimeter of the circle, equal to one-half the length of the diameter
Rapid:
moving very quickly
Rapt:
being completely occupied by, or focused on, something
Ratio:
a comparison between two quantities (for example, the ratio of girls
to boys in the class is 1:2)
Real number line:
an infinite line of real numbers represented on a one-dimensional
graph
Real numbers:
numbers that can be associated with points on a number line
Recount:
to describe the facts or details of a past event; to retell a story or
repeat testimony
Rectangular:
having the shape of a rectangle (a parallelogram with four right
angles)
Recurrent:
taking place over and over
Redeem:
to pay off a debt or fulfill an obligation; to make good
Redirect:
to alter the course or direction
Rediscover:
to learn about or see something as though for the first time
Regular hexagon:
a six-sided figure with congruent sides and angles
Relevant:
logically connected; pertinent
Reluctant:
unwilling and resistant
Reparation:
compensation given to make amends
Resonate:
to produce or amplify vibrations
Respectively:
in the order given
Retention:
the ability to hold things in or retain
Rifling:
(v.) to search through, looking for something to steal; (n.) the spiral
grooves on the inside of a gun barrel
Rift:
a split or a break
Rotate vs. Revolve:
rotate: to turn about a fixed point; revolve: to turn on an axis
Rudimentary:
very basic or not fully developed
S
Sacrilege:
to misuse something that is sacred
Sanctuary:
a sacred place; a refuge
Saplings:
young trees
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APPENDIX 3
Saturation:
a state of being completely full or soaked
Sauropod:
a type of plant-eating dinosaur, for example, the brontosaur
Scientific inquiry:
based on experiment and observation and the application of the
Scientific Method; examination into facts or principles
Scrutiny:
very close examination
Sediment:
solid materials that sink to the bottom of a liquid
Seedling:
a young plant grown from seed
Seminal:
forms the basis for future development; at the beginning; original
Simultaneously:
happening or existing at the same time
Skepticism:
an attitude of doubt or disbelief
Social rituals:
specific gestures and behaviors that are observed by members of a
community
Solace:
comfort; safety
Solid:
neither gas nor liquid; of definite shape and volume
Solute:
a dissolved substance
Solution:
a mixture of two or more substances
Solution set:
the set of values that make an equation true
Sovereign:
(adj.) having supreme power; (n.) ruler or king
Span:
distance between two things
Specific gravity:
the ratio of the density of one substance to the density of another
substance
Speculators:
people who form theories based on uncertain evidence; those who
purchase something with the hope of reselling it later at a profit
Sphere:
a solid, round figure where all points on the surface are the same
distance from the center (for example, a basketball)
Spleen:
a vascular, ductless organ that is located in the left abdominal region
close to the stomach
Stagnant:
not moving or changing; stale
Standard (x, y)
coordinate plane:
a plane that is formed by a horizontal x-axis and a vertical y-axis
that meet at point (0,0) (also known as the Cartesian Coordinate
Plane)
Steerage passenger:
someone who rides in the least expensive section of a ship
Straddle:
having one leg on each side of something
Stratosphere:
a layer of the atmosphere between the troposphere and mesosphere
Subcontractor:
someone who agrees to perform one part of a larger commitment or
contract
A C T V O C A B U L A RY L I S T
551
Subjective:
dependant on a person’s attitudes or opinions
Subsequent:
to come next or later
Subtropical:
near the tropical areas of the world; extremely humid and hot
climate
Sucrose:
a simple sugar
Summary:
(n.) a statement that has condensed a larger body of work; (adj.)
conducted without trial
Supercooled:
below freezing but remaining liquid
Suspensions:
the state of a substance when its particles are combined together but
have not been dissolved in a fluid or solid
Sustenance:
things that provide nourishment for survival
Synchronized:
occurring at the same time and at the same rate
Synthesis:
combining separate elements to form a whole
Synthetic polymer:
a human-made, repeating chain of atoms
T
Tenet:
a belief that is held to be true by a certain group
Terrestrial:
relating to dry land as opposed to water; relating to the Earth as
opposed to other planets
Territorial:
the protective behavior that is displayed when an animal is
defending its area
Thermal degradation:
a process of combustion where materials in a fuel are broken down
into several by-products
Thermosphere:
the outermost layer of the atmosphere
Toxins:
poisons
Transcend:
to go above and beyond; to rise above
Translucent:
allowing light to pass through but clouded or frosted in such a way
that objects on the other side are not clearly visible; often confused
with transparent, which means ‘‘clear’’
Transversal:
a line that cuts through two or more lines
Trapezoid:
a quadrilateral (a figure with four sides) with only two parallel lines
Treason:
a betrayal of loyalty
Triannual:
lasting three years or occurring every three years
Tropical area:
an area near the equator that has a frost-free climate with high
temperatures that can support year-round vegetation
Troposphere:
the lowest part of the Earth’s atmosphere
Tyranny:
absolute power exercised by an oppressive ruler
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APPENDIX 3
U
Ultraviolet:
situated beyond the visible spectrum
Unemotional:
devoid of sentiment or emotion
Uniform:
(adj.) continuing to be the same or consistent; (n.) identical clothing
worn by members of a certain group
Unilaterally:
related to or occurring on one side only
Unparalleled:
without an equal or comparison
Unprecedented:
having no previous example
Unsolicited:
unwanted
V
Vapor pressure:
the pressure exerted by the molecules of a vapor
Vaporize:
to change into a cloud of diffused matter
Various:
of differing kinds
Velocity:
speed of motion
Vertical migrators:
marine species that travel toward the surface of the ocean to feed
Vertices:
the plural form of vertex, which is a point of intersection
Vindication:
the act of clearing someone or something from blame
Virtually:
in almost all instances; simulated as by a computer
Virus:
organism that causes infection
Viscosity:
a fluid’s resistance to flow
Visionary:
(adj.) characterized by dreams or illusions; (n.) a person with vision
or foresight
Voltage:
a measure of the energy of an electric current
W–Z
Wavelength:
the distance between repeating peaks or crests of waves
x-intercept:
the point where a line on a graph crosses the x-axis
y-intercept:
the point where a line on a graph crosses the y-axis