- 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.