Studying ACT Vocabulary

The ACT test consists of four multiple choice sections: English, mathematics, reading, and science. You also have the option to take the optional writing section after the multiple choice portion. 

Vocabulary plays an important role throughout the exam, as you’ll have to read through multiple passages and answer questions based on your reading comprehension (except in the mathematics section). As such, you should spend some time before your test date brushing up on some vocabulary to prepare yourself as much as possible. Especially in the English and reading sections, knowing the definitions and uses of some words might make a huge difference when you’re trying to decipher what a passage or excerpt is saying. 

In this guide to ACT vocabulary, we’ll discuss how the ACT tests student knowledge of vocabulary throughout the exam, list some common vocabulary words that have appeared on the ACT along with their definitions, and then provide some methods for how to best maximize your study time for vocabulary.

How Does The ACT Test Your Vocabulary?

The ACT will not ask direct questions about vocabulary (for instance, you will not have to answer a question that asks something along the lines of, “what does the word ‘affable’ mean”), but you will have to have a pretty strong grasp of different vocabulary terms in order to answer some questions. 

You will have to use your knowledge of vocabulary in three different ways throughout the ACT:

• To know what the author’s word choice and diction tells you about their tone, argument, or meaning
• To use context clues and surrounding language to infer the meaning of a word 
• To determine which word would best fit inside a sentence 

To prepare for the ACT, it’s important to have as strong of a grasp on vocabulary as possible, but as you can see, you’ll be able to use context clues and your comprehension skills in order to think about what an unknown word means. That being said, it’ll help you move through the exam more quickly and confidently if you have a wider vocabulary so you should at least spend some time every study session brushing up on common ACT words. 

How The ACT Tests Vocabulary: Diction And Author’s Word Choice 

One of the ways the ACT will test your understanding of vocabulary is through questions asking about the author’s choice of diction. Diction refers to the words the author uses to convey their message. Understanding diction can help you infer the author’s tone and therefore help with comprehension of the passage’s theme. 

How The ACT Tests Vocabulary: Inferring Meaning Using Context Clues

Another way the ACT tests vocabulary is through questions that ask you to infer what an unfamiliar, ambiguous, or advanced word means in the context it is used. Sometimes, it’ll ask you about a common word but you should always go back into the passage to read the context because it may not be used in the way you typically expect. 

How The ACT Tests Vocabulary: Determining The Best-Fitting Word 

A different way the ACT tests your vocabulary is through questions asking which word answer choice works best in the provided sentence. You will either choose to keep the suggested word, or replace it with other options. If you have a stronger grasp on vocabulary, it’ll be easier to eliminate unfit words in the answer choices. A good vocabulary, along with strong comprehension skills and an ability to use context clues, will help you answer these questions and choose the best fitting word for the sentence. Make sure to read the sentences preceding and following the one you are modifying to fully understand the context! 

Top List Of 130 ACT Vocabulary Words With Definitions

1. Abundant (adjective): present in large quantities
2. Adamant (adjective): refusing to change an opinion 
3. Adhere (verb): stick completely to a surface or substance, or to believe in and follow the practices of  
4. Adverse (adjective): unfavorable and against one’s desires 
5. Affable (adjective): friendly and easy to talk to
6. Ambiguous (adjective): having different potential meanings, unclear and difficult to parse or understand clearly
7. Anecdote (noun): a short, interesting or funny story about a real event or person
8. Antagonize (verb): to provoke someone, to cause them to become hostile or aggressive 
9. Anticipate (verb): to expect or predict, to view something as likely to happen 
10. Antipathy (noun): a very strong feeling of dislike for someone or something, aversion
11. Apprehensive (adjective): afraid or anxious that something negative will happen
12. Arcane (adjective): mysterious or secretive 
13. Assert (verb): state a fact, opinion, or belief confidently and forcefully, or to cause others to recognize their authority through confident or forceful behavior
14. Assess (verb): to consider, evaluate, or estimate the nature, ability, or quality of something, or to calculate the expected price or value of something
15. Attribute (verb): regard something as being caused by someone or something; also attribute (noun): quality or feature thought to be characteristic of someone or something
16. Bear (verb): support or carry the weight of something, endure
17. Befall (verb): happen to someone (used for negative events)
18. Benevolent (adjective): kind, well meaning; (of an organization) serving a charitable purpose instead of profit 
19. Burgeon (verb): flourish, begin to grow or increase quickly 
20. Candid (adjective): frank, truthful and straightforward 
21. Candor (noun): the quality of being honest and open in expression, frank
22. Coherent (adjective): (of an argument) logical and consistent; also coherent (adjective): united as a whole or forming a whole 
23. Compassion (noun): sympathetic pity and concern for the sufferings or misfortunes of other people
24. Compensate (verb): to give someone something, usually money, in recognition of injury, loss, or suffering
25. Complement (verb): to add to something in a way that enhances and improves it, to make perfect; also complement (noun): a thing that makes something perfect or completes it
26. Compose (verb): to create, usually referring to writing or creating a work of art like music and poetry; or compose (verb): to constitute or make up a whole
27. Condescending (adjective): having or showing a feeling of patronizing superiority, patronizing 
28. Consecutive (adjective): following continuously, successive 
29. Contour (noun): an outline, especially one representing or bounding the shape or form of something
30. Contract (verb): to decrease in size, number, or range
31. Contradict (verb): to deny the truth of a statement by asserting the opposite, to refute or be in conflict with 
32. Correlate (verb): to have a mutual relationship or connection in which one thing either affects or depends on another 
33. Critical (adjective): expressing disappointing or negative comments or judgements about someone or something; or critical (adjective): an analysis of the merits and faults of a work of literature, music or art
34. Cumbersome (adjective): heavy, unwieldy, large, or unmanageable, making it hard to use or carry; or cumbersome (adjective): inefficient because of its complicated or slow nature 
35. Deficit (noun): the amount by which something is too small or is lacking, like a sum of money 
36. Demean (verb): humiliating or degrading something, causing it to have a loss in dignity or respect; or demean (verb): to do something that is beneath one’s dignity
37. Depict (verb): to represent or show something through painting, drawing, words, or other forms 
38. Determine (verb): to cause something to occur in a specific way, to be the decisive factor; or determine (verb): to establish or ascertain something, usually from research or calculation
39. Devoid (adjective): completely lacking or free from something
40. Differentiate (verb): to recognize and pinpoint what makes something or someone different from something or someone else 
41. Diffuse (verb): spread or cause to spread over a wide area or among many people 
42. Digress (verb): leave the main subject for a temporary period in a speech or writing
43. Diminish (verb): to make less or become less; also diminish (verb): to make someone or something seem less impressive or valuable, to disparage 
44. Discrepancy (noun): a lack of compatibility or similarity between two or more facts 
45. Disinclined (adjective): unwilling or reluctant to do something, unenthusiastic
46. Dismantle (verb): to take apart a machine or structure, to disassemble or break down into pieces 
47. Dismay (noun): distress, surprise, or concern, usually caused by something unexpected or unforeseen
48. Disposition (noun): a person’s temperament, or inherent qualities of mind and character 
49. Dynamic (adjective): characterized by constant change, activity, or progress (when describing a process, institution, or system) or positive in attitude and full of energy and new ideas (when describing a person) 
50. Eclipse (verb): to deprive someone or something of significance, power, or prominence 
51. Emerge (verb): move out or away from something and come into view, to appear 
52. Eminent (adjective): famous or respected within a particular sphere or profession, distinguished; or eminent (adjective): used to emphasize the presence of a positive quality
53. Engage (verb): to occupy, attract, or involve someone’s interest or attention, or to participate or become involved in 
54. Engross (verb): to absorb all the attention or interest of, to engage or preoccupy someone’s attention 
55. Ethereal (adjective): extremely delicate and light in a way that seems too perfect for the world 
56. Erode (verb): to gradually wear away, to gradually destroy or be gradually destroyed 
57. Evolve (verb): to change or develop slowly often into a better, more complex, or more advanced state 
58. Exploit (verb): to make full use of and derive benefit from a resource; or exploit (noun): a bold or daring feat
59. Facilitate (verb): to make an action or process easy or easier 
60. Fastidious (adjective): very attentive to and concerned about accuracy and details, meticulous
61. Feign (verb): to pretend to be affected by a feeling, state, or injury
62. Fleeting (adjective): lasting for a very short or brief period of time, short lived 
63. Fluctuate (verb): rise and fall irregularly in number or amount 
64. Frenetic (adjective): fast and energetic in a rather wild and uncontrolled way 
65. Glaring (adjective): giving out or reflecting a strong or dazzling light, blinding light
66. Grandeur (noun): splendor and impressiveness, especially of appearance or style
67. Hardship (noun): severe suffering 
68. Hurtle (verb): move or cause to move at a great speed, usually in a wildly uncontrolled manner 
69. Hostile (adjective): unfriendly, antagonistic, aggressive, or opposed 
70. Hypothetical (adjective): involving or being based on a suggested idea or theory, being or involving a hypothesis 
71. Imminent (adjective): about to happen, impending or close 
72. Immobile (adjective): not moving, motionless 
73. Impervious (adjective): unable to be affected by, immune to; or impervious (adjective): not allowing fluid to pass through, impermeable 
74. Incendiary (adjective): designed to cause fire, explosive 
75. Incompetent (adjective): not having or showing the necessary skills to do or complete something successfully, inept 
76. Infer (verb): deduce or conclude information from evidence and reasoning rather than from explicit statements, to reason 
77. Inhibit (verb): to hinder, restrain, or prevent an action or process 
78. Intricate (adjective): very complicated or detailed, complex 
79. Justify (verb): show or prove to be right or reasonable
80. Lack (noun): the state of being without something or not having enough of something, absence 
81. Lethargic (adjective): affected by lethargy, sluggish and apathetic
82. Latter (adjective): referring to the second or second mentioned of two people or thing; or latter (adjective): situated or occurring nearer to the end of something than to the beginning
83. Listless (adjective): describing a person or their manner whose is lacking energy or enthusiasm 
84. Lucrative (adjective): producing a great deal of profit 
85. Malicious (adjective): characterized by malice, intending or intended to do harm, spiteful
86. Malleable (adjective): easy influenced and pliable, suggestible 
87. Minute (adjective): extremely small, so small as to verge on insignificance 
88. Modify (verb): make partial or minor changes to something, typically so as to improve it or to make it less extreme
89. Momentous (adjective): something, like a decision, event, or change, that is of great importance or significance, especially in its bearing on the future, important 
90. Notion (noun): a conception of or a belief about something
91. Novel (adjective): new or unusual in an interesting way, original 
92. Obsolete (adjective): no longer produced or used, out of date 
93. Obstruct (verb): to block an opening, path, road, or something else, to be or get in the way of; or obstruct (verb): to prevent or hinder the movement of someone or something in motion, to deliberately make something difficult 
94. Omit (verb): leave out or exclude someone or something, either intentionally or forgetfully 
95. Omnipotent (adjective): having unlimited power, able to do anything and knowing everything 
96. Paradox (noun): a seemingly absurd or self contradictory statement or proposition that when investigated or explained may prove to be well founded or true 
97. Paramount (adjective): more important than anything else, supreme 
98. Peril (noun): serious and immediate danger, risk 
99. Perpetual (adjective): never ending or changing, occurring so frequently so as to seem endless and uninterrupted 
100. Pragmatic (adjective): dealing with things sensibly and realistically in a way that is based on practical rather than theoretical considerations
101. Precede (verb): to come before something in time 
102. Precise (adjective): marked by exactness and accuracy of expression or detail 
103. Prestigious (adjective): inspiring respect and admiration, having high status 
104. Profound (adjective): having intellectual depth and insight
105. Prolific (adjective): present in large numbers or quantities, plentiful
106. Pungent (adjective): having a sharply strong taste or smell
107. Qualitative (adjective): relating to, measuring, or measured by the quality of something rather than its quantity
108. Quantitative (adjective): relating to, measuring, or measured by quantity of something rather than its quality
109. Radical (adjective): very different from the usual or traditional, extreme 
110. Redundant (adjective): not or no longer needed or useful, superfluous
111. Resent (verb): feel bitterness or indignation at a circumstance, action, or person
112. Revive (verb): restore to life or consciousness
113. Rigorous (adjective): extremely thorough, exhaustive, or accurate
114. Rudimentary (adjective): involving or limited to basic principles
115. Skeptical (adjective): not easily convinced, having doubts or reservations
116. Solemn (adjective): formal and dignified, not cheerful or smiling, serious
117. Static (adjective): lacking in movement, action, or change, especially in a way viewed as undesirable or uninteresting
118. Staunch (adjective): loyal and committed in attitude, faithful
119. Strenuous (adjective): requiring or using great exertion
120. Subversive (adjective): seeking or intended to subvert an established system or institution, disruptive
121. Sumptuous (adjective): splendid and expensive looking
122. Tedious (adjective): too long, slow, or dull, tiresome or monotonous
123. Tentative (adjective): not certain or fixed, provisional
124. Trivial (adjective): of little value or importance, insignificant
125. Ubiquitous (adjective): present, appearing, or found everywhere 
126. Unprecedented (adjective): never done or known before 
127. Validate (verb): check or prove the validity or accuracy of something; or validate (verb): demonstrate or support the truth or value of 
128. Viability (noun): ability to work successfully
129. Vital (adjective): absolutely necessary or important, essential
130. Void (adjective): not valid or legally binding, completely empty

*Many of these definitions were taken from Oxford Languages.

Certain words in this list can be confusing to see in the ACT if you’re not familiar with them, like the word “complement.” For instance, if you see the word complement used in a passage and don’t know the meaning you might confuse it with the word “compliment.” Where compliment means a polite expression of praise or admiration, complement means to complete something or enhance it to make it perfect. 

Knowing the subtle difference between the two (compliment vs. complement) might completely shift your understanding of the passage’s context and meaning, so if you can incorporate a bit of vocabulary into your ACT study plan you might help your comprehension skills on test day. 

Not all of these words will appear on the ACT, but they are pretty common words that you might expect to see in both the ACT and the SAT. You don’t need to memorize the exact definition and use of every single word on this list, but if you struggle with vocabulary and are looking for a list of words to go over before your exam, this is a great place to start. 

As we discussed earlier, the ACT is not a vocabulary test, so you don’t need to worry about strict memorization of certain words. Based on the types of questions the ACT uses to test your grasp of vocabulary, you should focus more on understanding how to decipher context clues to determine meaning over just memorizing as many words as possible. However, the more words you are familiar with, the easier it will be to understand context clues. You will benefit from improving your vocabulary, but just keep in mind that it’s not just about memorization!

How To Practice ACT Vocabulary 

If you’ve decided that you need a bit of help expanding your vocabulary, there are many different methods you can try out. This section will go over some common strategies that people use to learn more vocabulary words. 

Word Of The Day Method

Once you have access to a list of commonly used ACT words, you might consider the word of the day approach to learning vocabulary. In the word of the day method, you choose one word per day to learn the definition of. You might do this by going down a list chronologically everyday, reading the definition of the word of the day and trying to use it in context. Throughout the day, you should try to apply the word to everyday thoughts, actions, or sentences. If you are able to do this with a friend, it can become a game to sneak it into your conversations, which will help you remember the word later on, especially if it was used in a funny or personal context. 

Some online websites also provide a word of the day, like online dictionary pages. If you want a website to choose a word of the day for you, then you might want to consider bookmarking one of those pages and returning to it everyday. However, you should keep in mind that the dictionary websites will just show a random word everyday, not necessarily common words that might appear on the ACT. 

Waterfall Method

One of the most popular ways to study vocabulary words, the waterfall method is a great way to expand your knowledge especially if you already have a pretty good base understanding of common ACT or SAT vocabulary terms. 

First, start with index cards of around 30-50 vocabulary words with their definitions on the back. As you review each card, begin to separate them into different piles. For instance, if you read a term and immediately recognize the word’s definition, place the card into a “know it” pile. If you don’t remember the definition as you read the word, place it in a second pile, the “struggled” pile. Once you have sorted through all of the words, start again with your “struggled” pile and sort out the words into two piles again: “know it (2)” and “struggled.” Continue this process until you only have a few words left in your “struggled” pile. 

At this point, you should have been reviewing all of the words in your vocabulary cards. Now, you will work your way “back up” the waterfall. Start by combining your “struggled pile” with the last “know it” pile you have. From this combined pile, review the words — if you forget the definition of even one of them, go through the entire pile again. While it may seem like a huge hassle, it’s the most foolproof way to make sure you really gain the strongest grasp of the vocabulary words that you can. If you make it through the entire pile, combine it with the next most recent “know it” pile and repeat the process. 

Eventually, you should end up with one stack of cards at the end. This method is pretty time consuming, so it’s not necessarily the best method to learn vocabulary if you are operating under a time crunch before your next ACT test date. However, it’s an effective and thorough way to make sure you really understand the meanings of every word in your pile. 

If creating these stacks of cards is too time consuming, Quizlet has a similar function with their online flashcard method. When reviewing your Quizlet, you have the option to mark cards you struggled with and did not grasp. If you want to try something similar to the Waterfall Method for vocabulary but don’t want to make all of the physical cards, consider creating a virtual study set on Quizlet.

Additional Recommendations

Another strategy to consider is to expand the amount of time you spend reading. Reading will help improve your grasp of vocabulary but, more importantly, will get you more familiar and comfortable with reading for longer periods of time and understanding the meaning of different texts. If you spend more time reading, whether it’s a fictional book for fun or articles from the New York Times, you will inadvertently end up improving your vocabulary and your reading comprehension skills. 

Additionally, when you’re completing practice exams and sections for the ACT, make sure you mark which words you don’t understand or have never seen before. After you complete the exam or section and are reviewing, you can look up the definitions of all the words you didn’t know. Learning these words within the context of different ACT passages and sentences will also help them stick in your mind, because you’ve seen them used in a sentence rather than just reading their definition somewhere. You can also compile all of the unfamiliar words you saw into a document or set of flashcards to review whenever you have the chance. 

Prepare For The ACT With SoFlo Tutors

Improving your vocabulary can have a huge impact on your ACT score, and working with a tutor can help you reach your full potential on the ACT. SoFlo Tutors employs top scoring tutors from elite universities who provide individualized support for each student to fit their specific needs. Check out our website and schedule a free consultation call to find out more today.

About The Author

Emily is a senior at the University of Pennsylvania and will be working as a Marketing Analyst in New York City after graduation. In her free time, she enjoys painting and playing the guitar.