183 Adjectives That Start With I

Close to three fifths of the adjectives in this letter are negations — in-, im- and ir- attached to a word that already existed. That makes I unusually easy to use and unusually easy to use lazily: not accurate and inaccurate are not quite the same sentence, and the second only earns its place when the failure is a property of the thing rather than a one-off.

This page lists 183 adjectives that start with I, each with its meaning and a short example. No negation below is glossed by repeating its own root, because “inaccurate: not accurate” teaches nobody anything — though where a word genuinely means the absence of something, the gloss says so.

All 183 adjectives, with meanings and examples

The full reference. Everything below this table is a cut of it, chosen for a particular job.

The twenty most useful

If you take twenty words from this page, take these — the ones that do work no other word on the list quite does.

1. inscrutable — gives nothing away, which is different from hiding something
2. incisive — the best single word of praise for a question
3. insidious — harm that works slowly and out of sight
4. ingenuous — open and unsuspecting — and constantly confused with its near-twin
5. implacable — opposition that cannot be bought off
6. incongruous — the precise word for something that does not belong
7. indolent — laziness with a settled, almost comfortable quality
8. impassive — no feeling shown, which is not the same as none felt
9. intractable — stubborn resistance, in a person or a problem
10. inordinate — excess, stated without raising the voice
11. innocuous — harmless, usually said of something that looked otherwise
12. inimitable — the only word that says a thing cannot be copied at all
13. imperceptible — change too small to catch as it happens
14. intrepid — courage that goes looking for the difficulty
15. indefatigable — tireless, over a long stretch rather than a night
16. incorrigible — affectionate as often as it is critical
17. intrinsic — worth that does not depend on what anyone pays
18. impromptu — unprepared, and pleased about it
19. insufferable — the strongest polite word for a person
20. illuminating — praise for something that made a thing clear

The positive ones

Praise-side words. Ingenious and ingenuous are one letter apart and mean entirely different things: the first is clever, the second is innocent.

ideal, idyllic, illuminating, illustrious, imaginative, immaculate, impartial, impeccable, impressive, incisive, inclusive, indefatigable, indispensable, indomitable, influential, informative, ingenious, innovative, insightful, instructive, intelligent, intrepid, inventive, invaluable

The negative ones

Criticism-side words. Insufferable is the one most often said out loud, and the one that carries the least argument with it.

idiotic, ignorant, illicit, immoral, impertinent, imperious, imprudent, inadequate, inane, incompetent, inconsiderate, incorrigible, indolent, inept, inexcusable, infamous, insensitive, insidious, insincere, insolent, insufferable, intolerant, intrusive, irresponsible

Describing appearance

I is thin on appearance and rich on manner. Imposing and impassive are the ones that do most of the work on a person.

icy, immaculate, immobile, imposing, impassive, inconspicuous, intricate, ivory

Common mistakes

Related guides

• Adjectives for intelligence — where incisive, ingenious and insightful do their closest work.
• Adjectives for ideas — expands innovative, intriguing and implausible.
• Adjectives for insights — pairs with illuminating and instructive.
• Adjectives for interaction — for intrusive, inclusive and intimate.
• Adjectives for investment — for incremental, intrinsic and invaluable.
• Adjectives for Italy — a subject guide where idyllic and illustrious earn their place.

Checked against Merriam-Webster, the Chicago Manual of Style and the AP Stylebook. Spotted an error? Tell us — see our editorial policy.