This list includes 72 SAT words that start with I, ranging from “iconoclast” to “itinerary”. They are concise, exam-focused vocabulary often appearing in reading passages, sentence completions, and essay prompts.
[SAT words that start with I] are high-value vocabulary items that improve your reading and writing performance. Many derive from Latin or Greek, with examples like “iconoclast” showing long cultural histories.
Below you’ll find the table with Word, Difficulty, Definition, and Example sentence.
Word: The vocabulary term itself, which you can click or scan to focus on meanings and usage.
Difficulty: A simple easy/medium/hard tag that helps you prioritize study time and practice focus.
Definition: A concise one-line dictionary-style meaning you can memorize and compare with synonyms or antonyms.
Example sentence: A clear, exam-style sentence showing typical context so you can see natural usage.
SAT words that start with I
| Word | Difficulty | Part of Speech | Definition |
|---|---|---|---|
| iconoclast | hard | noun | person who attacks cherished beliefs or institutions |
| idiosyncrasy | hard | noun | distinctive habit or characteristic peculiar to an individual |
| illicit | medium | adjective | forbidden by law, rules, or custom |
| illusory | hard | adjective | based on illusion; deceptive or misleading |
| illustrious | medium | adjective | notably outstanding because of dignity or achievements |
| imbue | medium | verb | to inspire or permeate with a feeling or quality |
| impeccable | medium | adjective | without fault or error; flawless |
| impecunious | hard | adjective | having little or no money; poor |
| immutable | hard | adjective | unchangeable over time; unalterable |
| impartial | medium | adjective | treating all parties or rivals equally |
| impasse | medium | noun | a deadlock or stalemate with no resolution |
| implacable | hard | adjective | unable to be calmed or appeased |
| implicit | medium | adjective | implied though not plainly expressed |
| implore | medium | verb | to beg earnestly and desperately for something |
| impetuous | hard | adjective | acting quickly without thought or care |
| impede | medium | verb | to obstruct or slow the progress of |
| impervious | hard | adjective | not affected or influenced by something |
| impertinent | hard | adjective | rude or improperly forward; irrelevant to matter |
| imperative | medium | adjective | extremely necessary or urgent; authoritative |
| impugn | hard | verb | to dispute the truth or honesty of a claim |
| incendiary | hard | adjective | tending to inflame or provoke controversy |
| incentive | easy | noun | a thing that motivates or encourages action |
| incipient | hard | adjective | beginning to exist or appear; initial |
| incisive | hard | adjective | clear and direct; sharply analytical or perceptive |
| incorrigible | hard | adjective | not able to be corrected or reformed |
| incontrovertible | hard | adjective | not open to question or dispute; indisputable |
| incongruous | medium | adjective | out of place; inconsistent with surroundings or expectations |
| incredulous | medium | adjective | unwilling or unable to believe something |
| indigenous | medium | adjective | originating naturally in a particular place |
| indolent | hard | adjective | habitually lazy or avoiding activity |
| indomitable | hard | adjective | impossible to subdue or defeat |
| indulgent | medium | adjective | willing to allow excessive leniency or pleasure |
| inert | medium | adjective | lacking the ability or strength to move |
| infer | medium | verb | to conclude information from evidence and reasoning |
| inherent | medium | adjective | existing as a natural, essential part of something |
| inhibit | medium | verb | to restrain or hinder an action or process |
| inimical | hard | adjective | hostile or harmful to someone or something |
| innocuous | medium | adjective | not harmful or offensive |
| innovate | medium | verb | to introduce new methods, ideas, or products |
| inscrutable | hard | adjective | impossible to understand or interpret |
| insidious | hard | adjective | proceeding in a subtle but harmful way |
| insinuate | medium | verb | to suggest or hint something indirectly and unpleasantly |
| insipid | medium | adjective | lacking flavor, interest, or stimulation |
| insolvent | hard | adjective | unable to pay debts owed; bankrupt |
| insolent | hard | adjective | showing rude or arrogant lack of respect |
| instigate | medium | verb | to provoke or bring about an action or event |
| integral | medium | adjective | necessary to make a whole complete; essential |
| integrity | medium | noun | quality of being honest and having strong moral principles |
| intelligible | medium | adjective | able to be understood; clear |
| intermittent | hard | adjective | occurring at irregular intervals; not continuous |
| interminable | hard | adjective | endless or seemingly endless; monotonously long |
| interrogate | medium | verb | to ask questions aggressively or formally |
| intervene | medium | verb | to come between disputing people or events to alter outcome |
| intimate | hard | verb | to imply or communicate subtly; to hint |
| intricate | medium | adjective | very complicated or detailed |
| intrinsic | medium | adjective | belonging naturally; essential to something’s nature |
| introspective | hard | adjective | characterized by self-examination and reflection |
| intuition | medium | noun | ability to understand something instinctively, without reasoning |
| inundate | medium | verb | to overwhelm with things or people to be dealt with |
| invoke | medium | verb | to call on a principle, law, or authority for support |
| inveterate | hard | adjective | having a long-established habit unlikely to change |
| inveigh | hard | verb | to speak or write about something with great hostility |
| inveigle | hard | verb | to persuade by flattery or deception; to entrap |
| invincible | medium | adjective | too powerful to be defeated or overcome |
| irascible | hard | adjective | easily made angry; prone to temperamental outbursts |
| ironic | medium | adjective | expressing meaning by using language that signifies opposite |
| irrational | medium | adjective | not logical or reasonable; lacking sound judgment |
| irrefutable | hard | adjective | impossible to deny or disprove; conclusive |
| irreverent | hard | adjective | showing lack of proper respect for serious subjects |
| irrelevant | medium | adjective | not connected or applicable to the matter at hand |
| itinerant | hard | adjective | traveling from place to place for work or duty |
| itinerary | medium | noun | a planned route or journey; travel schedule |
Descriptions
iconoclast
A critic of established traditions or icons; often used for cultural skeptics. Example: The iconoclast questioned long-held artistic conventions.
idiosyncrasy
A quirky trait or behavioral peculiarity that distinguishes a person. Example: Her habit of whistling during meetings was an endearing idiosyncrasy.
illicit
Describes illegal or unauthorized actions; common on practice passages. Example: The police seized the illicit goods.
illusory
Refers to something that seems real but is false or misleading. Example: The promised gains proved illusory.
illustrious
Describes someone widely respected for achievements or reputation. Example: The illustrious scientist won multiple awards.
imbue
To fill something or someone with a particular quality or influence. Example: The teacher sought to imbue students with curiosity.
impeccable
Means flawless in behavior, taste, or quality. Example: Her presentation was impeccable.
impecunious
A formal term for financially poor or penniless. Example: The impecunious artist relied on patrons.
immutable
Describes something fixed or resistant to change. Example: Laws of physics are often treated as immutable.
impartial
Fair, unbiased judgment or treatment. Example: The judge remained impartial during the trial.
impasse
A situation where progress is blocked and negotiation stalls. Example: Negotiations reached an impasse after hours.
implacable
Describes relentless hostility or inability to be satisfied. Example: She remained implacable after the betrayal.
implicit
Suggests unstated or understood meaning. Example: His nod gave implicit approval.
implore
To plead strongly for assistance or mercy. Example: She implored him to stay.
impetuous
Describes rash, impulsive behavior. Example: His impetuous decision led to regrets.
impede
To create difficulty or delay. Example: Traffic can impede emergency vehicles.
impervious
Resistant or immune to influence or penetration. Example: The coating made the fabric impervious to water.
impertinent
Can mean rude or not relevant in context. Example: His impertinent question annoyed the panel.
imperative
Describes something essential or commanding action. Example: It is imperative to follow safety rules.
impugn
To challenge someone’s integrity or the validity of an argument. Example: The report sought to impugn the witness’s credibility.
incendiary
Also describes something capable of causing fire; used figuratively. Example: The columnist’s incendiary remarks sparked debate.
incentive
A motivator or reward prompting behavior. Example: Bonuses act as incentives for performance.
incipient
Describes an early or emerging stage. Example: The incipient movement gained momentum quickly.
incisive
Describes mentally sharp or cutting remarks and analysis. Example: Her incisive critique improved the draft.
incorrigible
Used for habits or people resistant to change. Example: The incorrigible prankster kept misbehaving.
incontrovertible
Describes evidence or facts that cannot be denied. Example: The DNA results were incontrovertible.
incongruous
Something that clashes with context or seems odd. Example: His casual attire looked incongruous at the gala.
incredulous
Shows skepticism or disbelief. Example: She gave an incredulous laugh at the claim.
indigenous
Native to a region rather than introduced. Example: These crops are indigenous to the island.
indolent
Describes laziness or slothful behavior. Example: The indolent employee missed deadlines.
indomitable
Describes unconquerable spirit or resilience. Example: The team’s indomitable will secured victory.
indulgent
Describes permissive or lenient attitudes often by caregivers. Example: Her indulgent parents spoiled her.
inert
Can mean inactive chemically or physically. Example: The gas remained inert under those conditions.
infer
To deduce or draw a conclusion logically. Example: From the tracks, we infer he left recently.
inherent
Intrinsic quality or characteristic. Example: Risk is inherent in investing.
inhibit
To prevent or slow down behavior or growth. Example: Fear can inhibit creativity.
inimical
Describes adversarial forces or damaging conditions. Example: Policies inimical to progress slowed reform.
innocuous
Harmless remark or substance; often used in analysis. Example: The comment seemed innocuous enough.
innovate
To create or implement novel solutions. Example: The startup plans to innovate in education.
inscrutable
Mysterious or unreadable in expression or meaning. Example: His motives were inscrutable.
insidious
Describes gradual, treacherous harm or influence. Example: The disease was insidious and slow-acting.
insinuate
Often implies sly or manipulative suggestion. Example: She insinuated that he was guilty.
insipid
Dull or bland in taste or style. Example: The film’s plot was insipid.
insolvent
Financial term used in reading passages on business. Example: The company became insolvent after losses.
insolent
Boldly disrespectful behavior or speech. Example: His insolent reply angered the teacher.
instigate
To initiate or stir up events, often trouble. Example: They accused him of instigating the protest.
integral
Crucial component of a system or argument. Example: Trust is integral to any relationship.
integrity
Moral uprightness and consistency of character. Example: Her integrity earned widespread respect.
intelligible
Comprehensible language or explanation. Example: He rewrote the essay to be more intelligible.
intermittent
Stops and starts unpredictably; used in passages about patterns. Example: The region experienced intermittent rain.
interminable
Used to describe prolonged, tedious durations. Example: The meeting felt interminable.
interrogate
Questioning, especially by authorities. Example: Detectives will interrogate the suspect tonight.
intervene
To step in to influence or mediate. Example: The mediator intervened to calm talks.
intimate
To suggest indirectly or make known softly. Example: She intimated her displeasure without saying it outright.
intricate
Complex structure or pattern requiring careful analysis. Example: The watch’s mechanism was intricate.
intrinsic
Innate or inherent quality rather than external. Example: Curiosity is intrinsic to good scientists.
introspective
Inward-looking, reflective thinking about one’s feelings or motives. Example: After the loss, he became introspective.
intuition
An immediate, instinctive insight or gut feeling. Example: Her intuition warned her to wait.
inundate
To flood figuratively with tasks or literal water. Example: The inbox was inundated after the event.
invoke
To appeal to or cite for justification. Example: She invoked precedent in her argument.
inveterate
Firmly ingrained behavior or inclination. Example: He was an inveterate smoker.
inveigh
To protest or complain vehemently. Example: Critics inveighed against the policy.
inveigle
To coax or lure into doing something, often deceitfully. Example: He inveigled her into signing the contract.
invincible
Unbeatable strength or resilience, often hyperbolic. Example: The team seemed invincible that season.
irascible
Quickly provoked to anger; used for temper descriptions. Example: His irascible temperament caused frequent disputes.
ironic
Situational or verbal contrast between expectation and reality. Example: It’s ironic that it rained on their picnic.
irrational
Contrary to reason or sensible thought. Example: Panic led to irrational choices.
irrefutable
Describes proof or argument that cannot be contradicted. Example: The footage provided irrefutable evidence.
irreverent
Mocking or playful disrespect toward traditions or authority. Example: The comedian’s irreverent jokes shocked elders.
irrelevant
Off-topic or not pertinent to discussion. Example: The comment was irrelevant to the question.
itinerant
Describes peripatetic workers or lifestyles. Example: The itinerant teacher moved between villages.
itinerary
Outline of trip stops and timetable. Example: Our itinerary lists three cities in five days.