TOEFL Top 100 Vocabulary Words
The 100 most important academic words for TOEFL iBT. Each entry includes the part of speech, a clear definition, an example sentence in academic context, and the full word family.
100 words · Part of speech · Definition · Example · Word family
How to use this list: These 100 words appear frequently in TOEFL Reading passages and are commonly tested in vocabulary-in-context questions. Study the word family column to recognize all forms on the exam. For best retention, review 10 words per day using spaced repetition.
| # | Word | Part of Speech | Definition | Example Sentence | Word Family |
|---|---|---|---|---|---|
| 1 | analyze | verb | To examine something methodically and in detail. | Researchers analyzed data from three independent studies before drawing conclusions. | analyze / analysis / analytical / analytically |
| 2 | approach | noun/verb | A way of dealing with a situation or problem; to come near. | The researchers adopted a quantitative approach to measure behavioral change. | approach / approachable / unapproachable |
| 3 | assess | verb | To evaluate or estimate the nature, value, or ability of something. | Teachers assess student progress through both written tests and oral presentations. | assess / assessment / assessable |
| 4 | assume | verb | To suppose to be the case without proof; to take on a role. | Classical models assume that markets are perfectly efficient and rational. | assume / assumption / assumed / assumable |
| 5 | authority | noun | The power to give orders or make decisions; an expert in a field. | The study cites several authorities in the field of environmental science. | authority / authoritative / authorize / authorization |
| 6 | available | adjective | Able to be used or obtained; not occupied. | Funding was not available for the second phase of the research program. | available / availability / unavailable |
| 7 | benefit | noun/verb | An advantage or profit; to gain an advantage. | Regular exercise benefits both physical and mental health outcomes. | benefit / beneficial / beneficiary / beneficially |
| 8 | concept | noun | An abstract idea or general notion. | The concept of supply and demand is central to all market-based economic theory. | concept / conceptual / conceptualize / conceptually |
| 9 | consistent | adjective | Acting or done in the same way over time; compatible with. | The findings were consistent across all three experimental groups in the study. | consistent / consistency / consistently / inconsistent |
| 10 | context | noun | The circumstances that form the setting for an event or statement. | Vocabulary questions require students to understand words in their academic context. | context / contextual / contextualize / contextually |
| 11 | contract | noun/verb | A legally binding agreement; to make or become smaller. | Muscles contract in response to electrical signals from the nervous system. | contract / contraction / contractor / contractual |
| 12 | create | verb | To bring something into existence; to produce. | The industrial revolution created enormous social and economic upheaval. | create / creation / creative / creativity / creator |
| 13 | data | noun | Facts and statistics collected for reference or analysis. | The data clearly indicate a strong correlation between income and educational attainment. | data / database / dataset / data-driven |
| 14 | define | verb | To state or describe exactly the nature or scope of something. | Scientists must precisely define their variables before beginning an experiment. | define / definition / definitive / definitely / indefinite |
| 15 | derive | verb | To obtain something from a specified source; to reach a conclusion by reasoning. | The formula was derived from first principles of classical mechanics. | derive / derivation / derivative / derived |
| 16 | distribute | verb | To divide and give out in shares; to spread over an area. | Resources were distributed unevenly among the populations studied. | distribute / distribution / distributive / distributable |
| 17 | economic | adjective | Relating to economics or the economy; justified in terms of cost. | Economic growth in the region slowed considerably following the financial crisis. | economic / economically / economy / economics / economist |
| 18 | environment | noun | The natural world; the surroundings in which a person, animal, or plant lives. | Climate change poses an unprecedented threat to the global environment. | environment / environmental / environmentally / environmentalist |
| 19 | establish | verb | To set up on a permanent basis; to prove or demonstrate. | The study established a clear link between air quality and respiratory health. | establish / establishment / established / re-establish |
| 20 | evaluate | verb | To assess or appraise the value or condition of something. | Peer reviewers evaluate submitted manuscripts before they are published. | evaluate / evaluation / evaluative / re-evaluate |
| 21 | evidence | noun | The available facts or information indicating whether something is true. | Multiple lines of evidence support the theory of continental drift. | evidence / evident / evidently / evidential |
| 22 | factor | noun | A circumstance, fact, or influence that contributes to a result. | Socioeconomic factors significantly influence educational achievement outcomes. | factor / factored / factorial / factorize |
| 23 | financial | adjective | Relating to finance or the management of money. | Financial constraints limited the scope of the original research program. | financial / financially / finance / financer |
| 24 | formula | noun | A rule expressed in symbols; a set procedure for achieving a result. | The formula for calculating compound interest includes both principal and rate. | formula / formulate / formulation / formulaic |
| 25 | function | noun/verb | The purpose or role of something; to operate or work. | Mitochondria function as the primary energy-producing organelles of the cell. | function / functional / functionality / dysfunction |
| 26 | identify | verb | To recognize or establish who or what someone or something is. | Researchers identified three key variables that affected the experimental outcome. | identify / identification / identifiable / identity |
| 27 | income | noun | Money received, especially on a regular basis, for work or investment. | Countries with higher average income tend to have better health outcomes. | income / low-income / high-income / income-based |
| 28 | indicate | verb | To point out; to be a sign or symptom of something. | The data indicate a significant rise in global average temperatures since 1950. | indicate / indication / indicator / indicative |
| 29 | individual | adjective/noun | Single; separate; a single human being distinct from a group. | Individual variation in genetic makeup influences susceptibility to certain diseases. | individual / individually / individualism / individualize |
| 30 | interpret | verb | To explain the meaning of; to understand in a particular way. | Students must interpret complex academic texts accurately under time pressure. | interpret / interpretation / interpretive / misinterpret |
| 31 | involve | verb | To include as a necessary element; to make someone participate. | The research process involved collecting data from over 2,000 participants. | involve / involvement / involved / involving |
| 32 | issue | noun/verb | An important topic for debate; to supply or distribute officially. | Environmental issues are now central to international policy negotiations. | issue / issuing / re-issue |
| 33 | labor | noun | Work, especially hard physical work; the workforce. | Agricultural labor became increasingly mechanized during the twentieth century. | labor / laborious / laboriously / laborer |
| 34 | legal | adjective | Of or relating to the law; permitted by law. | The company faced legal challenges after the product recall was announced. | legal / legally / legality / illegal / illegality |
| 35 | method | noun | A particular form or way of doing something; a systematic procedure. | The scientific method requires hypotheses to be tested through controlled experiments. | method / methodical / methodology / methodically |
| 36 | occur | verb | To happen; to exist or be found somewhere; to come to mind. | The phenomenon occurs most frequently at high altitudes and low temperatures. | occur / occurrence / recurring / recur |
| 37 | percent | noun/adverb | A rate or proportion per hundred; by a specified amount in every hundred. | Approximately 70 percent of Earth's surface is covered by water. | percent / percentage / percentile |
| 38 | period | noun | A length or portion of time; a particular phase in history. | The Cretaceous period ended approximately 66 million years ago. | period / periodic / periodically / periodical |
| 39 | policy | noun | A course of action adopted by an organization or government. | Environmental policy must balance economic development with ecological protection. | policy / policymaker / policy-driven |
| 40 | principle | noun | A fundamental truth or law; a moral rule or standard. | The principle of conservation of energy underpins all of classical mechanics. | principle / principled / principally / unprincipled |
| 41 | process | noun/verb | A series of actions to achieve a result; to perform a series of operations on. | The fossilization process typically requires thousands of years. | process / processing / processor / re-process |
| 42 | require | verb | To need something; to make necessary. | Successful language acquisition requires both input and meaningful practice. | require / requirement / required / requisite |
| 43 | research | noun/verb | The systematic investigation of facts; to study a subject thoroughly. | Decades of research have confirmed the relationship between smoking and lung cancer. | research / researcher / research-based / re-search |
| 44 | respond | verb | To say or do something in reply or reaction. | The immune system responds to pathogens by producing specific antibodies. | respond / response / responsive / unresponsive |
| 45 | role | noun | The function assumed or part played in a particular situation. | Mycorrhizal fungi play a crucial role in forest nutrient cycling. | role / role-play / role-based |
| 46 | section | noun | A distinct part or portion; one of the parts into which something is divided. | The methodology section describes how participants were recruited and tested. | section / sectional / subsection / cross-section |
| 47 | significant | adjective | Sufficiently great or important to be worthy of attention. | The study found a statistically significant correlation between the two variables. | significant / significance / significantly / insignificant |
| 48 | similar | adjective | Resembling without being identical; comparable. | Similar results were observed in studies conducted across five different countries. | similar / similarity / similarly / dissimilar |
| 49 | source | noun | A place, person, or thing from which something originates. | Fossil fuels remain the dominant energy source in most industrialized economies. | source / sourcing / source-based |
| 50 | specific | adjective | Clearly defined or identified; precise. | The questionnaire asked participants about specific aspects of their daily diet. | specific / specifically / specificity / non-specific |
| 51 | structure | noun/verb | The arrangement of and relations between the parts of something complex. | The double-helix structure of DNA was confirmed by Watson and Crick in 1953. | structure / structural / structurally / restructure |
| 52 | theory | noun | A supposition intended to explain something; a well-substantiated scientific explanation. | Darwin's theory of evolution by natural selection revolutionized biology. | theory / theoretical / theoretically / theorize |
| 53 | vary | verb | To differ in size, amount, or degree; to change from one form to another. | Rainfall patterns vary considerably across different regions of the continent. | vary / variation / variable / variety / various |
| 54 | accumulate | verb | To gather together or acquire an increasing amount of something over time. | Pollutants accumulate in the food chain through the process of biomagnification. | accumulate / accumulation / cumulative / cumulatively |
| 55 | adequate | adjective | Sufficient for a specific need; acceptable but not exceptional. | Adequate nutrition in early childhood is essential for healthy brain development. | adequate / adequacy / adequately / inadequate |
| 56 | ambiguous | adjective | Open to more than one interpretation; not clear. | The results were ambiguous and required further experiments to interpret correctly. | ambiguous / ambiguity / ambiguously / unambiguous |
| 57 | apparent | adjective | Clearly visible or understood; seeming real but not necessarily so. | There is an apparent discrepancy between the two sets of experimental data. | apparent / apparently / appearance / unapparent |
| 58 | cease | verb | To stop; to come or bring to an end. | Industrial pollution ceased only after strict environmental regulations were enforced. | cease / cessation / ceaseless / ceaselessly |
| 59 | challenge | noun/verb | A task requiring effort; to dispute or call into question. | Scientists challenged the original hypothesis based on newly collected field data. | challenge / challenging / challenger / unchallenged |
| 60 | circumstance | noun | A fact or condition connected with or relevant to an event or action. | Under no circumstances should participants be subjected to unnecessary discomfort. | circumstance / circumstantial / circumstantially |
| 61 | cite | verb | To quote or refer to as evidence or justification. | The review article cites over 150 peer-reviewed studies as supporting evidence. | cite / citation / cited / citing |
| 62 | coherent | adjective | Logical and consistent; forming a unified whole. | A coherent argument requires evidence, logical reasoning, and a clear conclusion. | coherent / coherence / coherently / incoherent |
| 63 | complex | adjective/noun | Consisting of many different parts; not easy to understand. | The human immune system is a remarkably complex network of interacting components. | complex / complexity / complexly / simplify |
| 64 | component | noun | A part or element of a larger whole. | Critical thinking is a key component of academic success at university level. | component / componential |
| 65 | concentrate | verb | To focus attention on; to increase the proportion of a substance. | Pollutants tend to concentrate at higher trophic levels in marine food chains. | concentrate / concentration / concentrated / re-concentrate |
| 66 | conclude | verb | To arrive at a judgment or opinion by reasoning; to bring to an end. | The researchers concluded that early intervention produced significantly better outcomes. | conclude / conclusion / conclusive / inconclusive |
| 67 | confirm | verb | To establish the truth or correctness of something. | A second study confirmed the initial findings on antibiotic resistance. | confirm / confirmation / confirmed / unconfirmed |
| 68 | consequence | noun | A result or effect; importance or relevance. | The long-term consequences of deforestation extend well beyond the immediate region. | consequence / consequential / consequently / inconsequential |
| 69 | contrast | noun/verb | A difference when compared; to compare in order to show differences. | The study contrasts urban and rural populations on measures of social cohesion. | contrast / contrasting / contrastive / contrastingly |
| 70 | contribute | verb | To give something in order to help achieve something. | Multiple factors contribute to the development of metabolic syndrome. | contribute / contribution / contributor / contributing |
| 71 | controversy | noun | Prolonged public disagreement or debate, especially about a matter of opinion. | The study generated controversy because its methodology was considered flawed. | controversy / controversial / controversially / uncontroversial |
| 72 | crucial | adjective | Decisively important; critical. | Access to clean water is crucial for preventing the spread of infectious disease. | crucial / crucially |
| 73 | cultural | adjective | Relating to the ideas, customs, and social behavior of a society. | Cultural norms regarding dietary practices differ considerably across societies. | cultural / culture / culturally / multicultural |
| 74 | dimension | noun | An aspect or feature of a situation; a measurable extent of a kind. | The study examines both the social and economic dimensions of urban poverty. | dimension / dimensional / dimensionality / two-dimensional |
| 75 | diverse | adjective | Showing a great deal of variety; very different. | A diverse ecosystem is generally more resilient to environmental disruption. | diverse / diversity / diversify / diversification |
| 76 | dominate | verb | To have or exert control over; to be the most important factor. | Fossil fuels continue to dominate the global energy mix despite the growth of renewables. | dominate / dominant / dominance / domination |
| 77 | dramatic | adjective | Sudden and striking; relating to drama. | Advances in genomics have produced dramatic changes in medical diagnostics. | dramatic / dramatically / drama / dramatize |
| 78 | emerge | verb | To become apparent or known; to come out from a place or situation. | A consensus emerged from the conference that immediate policy action was necessary. | emerge / emergence / emergent / re-emerge |
| 79 | emphasis | noun | Special importance, value, or prominence given to something. | The curriculum places emphasis on developing critical thinking over rote memorization. | emphasis / emphasize / emphatic / emphatically |
| 80 | equivalent | adjective/noun | Equal in value, amount, function, or meaning. | One kilogram is equivalent to approximately 2.2 pounds in the imperial system. | equivalent / equivalence / equivalently / inequivalent |
| 81 | exclude | verb | To deny access to; to remove from consideration. | Participants were excluded from the study if they had pre-existing cardiac conditions. | exclude / exclusion / exclusive / exclusively |
| 82 | explicit | adjective | Stated clearly and in detail; leaving nothing implied. | The instructions should be explicit enough for any trained technician to follow safely. | explicit / explicitly / explicitness / implicit |
| 83 | expose | verb | To make visible; to subject someone to something. | Children exposed to multiple languages before age 5 show enhanced cognitive flexibility. | expose / exposure / exposed / unexposed |
| 84 | extensive | adjective | Covering a large area; having a wide scope. | Extensive fieldwork was conducted over a three-year period in four countries. | extensive / extensively / extent / extension |
| 85 | generate | verb | To produce or create something. | Solar panels generate electricity without producing any greenhouse gas emissions. | generate / generation / generator / generative |
| 86 | global | adjective | Relating to the whole world; comprehensive. | Global average temperatures have risen by approximately 1.1°C since pre-industrial times. | global / globally / globalize / globalization |
| 87 | impact | noun/verb | A significant effect or influence; to have a strong effect on. | The agricultural revolution had a profound impact on human population dynamics. | impact / impactful / high-impact |
| 88 | implement | verb | To put a plan, decision, or agreement into effect. | Governments implemented strict emission regulations to address air quality concerns. | implement / implementation / implementable |
| 89 | implications | noun | The conclusions that can be drawn from something; possible effects. | The implications of this research for public health policy are considerable. | implication / imply / implied / implicitly |
| 90 | insight | noun | The capacity to gain an accurate understanding; a deep perception. | The longitudinal study provided new insights into language development in bilinguals. | insight / insightful / insightfully |
| 91 | integrate | verb | To combine one thing with another to form a whole. | The new curriculum integrates technology with traditional teaching approaches. | integrate / integration / integral / disintegrate |
| 92 | maintain | verb | To keep in existence or continuance; to assert as true. | Ecosystems maintain stability through complex feedback loops among species. | maintain / maintenance / maintainable |
| 93 | mechanism | noun | A process by which something takes place; a system of parts working together. | The mechanism by which viruses evade the immune system varies across species. | mechanism / mechanical / mechanically / mechanize |
| 94 | network | noun | A system of interconnected things or people; an arrangement of intersecting lines. | The neural network of the brain processes information through billions of synaptic connections. | network / networking / interconnect |
| 95 | notion | noun | A concept or idea; a belief or opinion. | The notion that genes alone determine behavior has been largely discredited by research. | notion / notional / notionally |
| 96 | obtain | verb | To come into possession of; to acquire. | Data were obtained from a stratified random sample of 5,000 households. | obtain / obtainable / unobtainable |
| 97 | parallel | adjective/noun | Occurring simultaneously; lines that never meet; a comparison. | Parallel studies conducted independently in Europe and Asia yielded similar conclusions. | parallel / parallelize / unparalleled |
| 98 | primary | adjective | Of chief importance; earliest in time; first in order. | The primary objective of the intervention was to reduce hospital readmission rates. | primary / primarily / prime / primitive |
| 99 | proportion | noun | A part, share, or number considered in relation to a whole. | A disproportionate share of greenhouse gas emissions comes from the transportation sector. | proportion / proportional / proportionate / disproportionate |
| 100 | substantial | adjective | Of considerable importance, size, or worth. | Substantial evidence from clinical trials supports the efficacy of the new treatment. | substantial / substantially / insubstantial / substantiate |
| 101 | sustain | verb | To keep something going; to maintain; to endure without giving way. | Tropical forests sustain an enormous proportion of global biodiversity. | sustain / sustainable / sustainability / unsustainable |
| 102 | trend | noun | A general direction in which something is developing or changing. | A clear trend toward urbanization has been observed across all developing regions. | trend / trendy / trending / downtrend |
| 103 | underlying | adjective | Lying under or beneath; fundamental; existing beneath the surface. | The underlying cause of the economic crisis was a collapse of consumer confidence. | underlying / underlie / underlay |
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Learn word families
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Study in context
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