| Term | Definition |
| illicit | illegal, improper |
| illimitable | limitless |
| illusory | unreal, deceptive |
| illustrious | famous, renowned |
| imbue | to infuse; dye, wet, moisten |
| immaculate | spotless; free from error |
| immaterial | extraneous, inconsequential, nonessential; not consisting matter |
| immense | to bathe, dip; to engross, preoccupy |
| immobile | not moveable; still |
| immune | exempt;protected from harm or disease; unresponsive to |
| immunological | relating to immune system |
| immutable | unchangeable, invariable |
| impair | to damage, injure |
| impasse | blocked path, dilemma with no solution |
| impassioned | with passion |
| hygienic | clean, sanitary |
| hymn | religious song, usually of praise or thanks |
| hyperbole | purposeful exaggeration for effect |
| hyperventilate | to breathe abnormally fast |
| hypochondria | unfounded belief that one is often ill |
| hypocrite | person claiming beliefs or virtues he or she doesn't really possess |
| hypothetical | theoretical, speculative |
| iconoclast | one who attacks traditional beliefs |
| idealism | pursuit of noble goals |
| idiosyncrasy | peculiarity of temperament, eccentricity |
| ignoble | dishonorable, not noble in character |
| ignominious | disgraceful and dishonorable |
| ilk | type or kind |
| anathema | ban, curse; something shunned or disliked |
| ancillary | accessory; subordinate; helping |
| anecdote | short, usually funny account of an event |
| angular | characterized by sharp angles; lean and gaunt |
| animation | enthusiasm, excitement |
| animosity | hatred, hostility |
| annul | to cancel, nullify, declare void, or make legally invalid |
| anodyne | something that calms or soothes pain |
| anoint | to apply oil to, expecially as a sacred rite |
| anomaly | irregularity or deviation from the norm |
| anonymity | condition of having no name or an unknown name |
| antagonist | foe, opponent, adversary |
| antecedent (adj.) | coming before in place or time |
| antediluvian | prehistoric, ancient beyond measure |
| antepenultimate | third from last |
| anterior | preceding, previous, before, prior (to) |
| anthology | collection of literary works |
| conjecture | speculation, prediction |
| conjugal | pertaining to marriage |
| conjure | to evoke a spirit, cast a spell |
| connive | to conspire, scheme |
| consanguineous | of the same origin; related by blood |
| conscientious | governed by conscience; careful and thorough |
| consecreate | to declare sacred; dedicate to a goal |
| consensus | unanimity, agreement of opinion or attitude |
| consign | to commit, entrust |
| consolation | someting providing comfort or solace for a loss or hardship |
| consolidate | to combine, incorporate |
| consonant (adj.) | consistent with, in agreement with |
| constituent | component, part; citizen, voter |
| constrained | forced, compelled, confined, restrained |
| constraint | something that forces or compels; something that restrains or confines |
| construe | to explaine or interpret |