| A | B |
| iconoclast | destroyer of tradition |
| ignoble | not noble |
| ignominious | characterized by dishonor and disgrace |
| ignominy | dishonor; disgrace |
| imbibe | to drink in; absorb |
| imbue | to make wet; saturate; to inspire |
| imminent | about to occur; impending |
| immutable | unchanging |
| impale | to pierce with a sharp stake or point |
| impasse | a dead end |
| impassive | without emotion; expressionless |
| impeccable | flawless and faultless; not capable of sin |
| impending | about to take place |
| imperious | domineering; tyrannical |
| impropriety | not proper; not displaying propriety |
| impugn | to attack as false; criticize |
| impunity | freedom from punishment |
| impute | to attribute (expecially a crime or fault) to another |
| incessant | nonstop; ceaseless |
| incite | arouse; instigate |
| incognito | in disguise, so as not to be recognized |
| incommodious | lacking space |
| incontrovertible | indisputable; without question |
| incubus | a nightmare; mental burden |
| indolence | laziness |
| indomitable | unconquerable; impossible to dominate |
| inept | incompetent |
| ingenious | original; resourceful |
| ingenuous | showing childlike simplicity; innocent |
| insatiable | impossible to satisfy |
| inscrutable | enigmatic; difficult to understand |
| insensate | unconscious; lacking sensation |
| insidious | working or spreading stealthily; crafty; sly |
| insipid | lacking excitement; boring |
| intangible | not perceptible to the touch |
| invective | abusive put-down |
| invidious | making people angry; offensive |
| irascible | easily provoked; irritable |