| infamy | Total loss or destitution of honor or reputation. |
| inference | The derivation of a judgment from any given material of knowledge on the ground of law. |
| infernal | Akin to or befitting hell or its occupants. |
| infest | To be present in such numbers as to be a source of annoyance, trouble, or danger. |
| infidel | One who denies the existence of God. |
| infidelity | Disloyalty. |
| infinite | Measureless. |
| infinity | Boundless or immeasurable extension or duration. |
| infirm | Lacking in bodily or mental strength. |
| infirmary | A place for the reception or treatment of the sick. |
| infirmity | A physical, mental, or moral weakness or flaw. |
| inflammable | Easily set on fire or excited. |
| inflammation | A morbid process in some part of the body characterized by heat, swelling, and pain. |
| inflexible | That can not be altered or varied. |
| influence | Ability to sway the will of another. |
| influential | Having the power to sway the will of another. |
| influx | Infusion. |
| infrequence | Rareness. |
| infrequent | Uncommon. |
| infringe | To trespass upon. |
| infuse | To instill, introduce, or inculcate, as principles or qualities. |
| infusion | The act of imbuing, or pouring in. |
| ingenious | Evincing skill, originality, or cleverness, as in contrivance or arrangement. |
| ingenuity | Cleverness in contriving, combining, or originating. |
| ingenuous | Candid, frank, or open in character or quality. |
| inglorious | Shameful. |
| ingraft | To set or implant deeply and firmly. |
| ingratiate | To win confidence or good graces for oneself. |
| ingratitude | Insensibility to kindness. |
| ingredient | Component. |
| inherence | The state of being permanently existing in something. |
| inherent | Intrinsic. |
| inhibit | To hold back or in. |
| inhospitable | Not disposed to entertain strangers gratuitously. |
| inhuman | Savage. |
| inhume | To place in the earth, as a dead body. |
| inimical | Adverse. |
| iniquity | Gross wrong or injustice. |
| initiate | To perform the first act or rite. |
| inject | To introduce, as a fluid, by injection. |
| injunction | Mandate. |
| inkling | A hint. |
| inland | Remote from the sea. |
| inlet | A small body of water leading into a larger. |
| inmost | Deepest within. |
| innocuous | Harmless. |
| innovate | To introduce or strive to introduce new things. |
| innuendo | Insinuation. |
| innumerable | Countless. |
| inoffensive | Causing nothing displeasing or disturbing. |