| Term | Definition |
| humanist | a person devoted to the humanities, or with a strong concern for human values and dignity |
| ideology | the ideas that guide a political group |
| imminent | about the occur at any moment |
| impassive | showing or feeling no emotion |
| imperil | to put into danger or peril |
| imperturbable | unable to be upset; calm |
| impervious | incapable of being harmed or penetrated |
| implant | to plant securely, especially in the mind, as habits, ideas, etc. |
| incarcerate | to imprison |
| incense | to make angry, to enrage |
| indeterminate | not fixed or determined, vague |
| inexplicable | can't be explained, not explicable |
| infest | to overrun, to live within to an unwanted degree |
| insinuate | to suggest slyly or indirectly, to hint at something negative |
| insoluble | can't be solved |
| instill | to put or infuse gradually, especially into the mind or character |
| intelligible | understandable |
| interrogate | to ask questions in a formal and thorough manner, especially when the police do it |
| intractable | stubborn, unmanageable |
| intrinsic | a basic part of something; inherent, innate, fundamental |
| invaluable | priceless; beyond calculable value or price |
| invariable | unchanging, static |
| invoke | to call on for aid; to appeal to for help |
| invulnerable | unable to be wounded or damaged, can't be attacked |
| irascible | easily irritated or angered |
| irresolute | not resolute, unsure of what you are going to do, vacillating |
| keen | sharp |
| latent | present but hidden or potential |
| lattice | a structure made up of crossed elements, such as sticks, metal strips or even chemical bonds |
| Limerick | a humorous poem of the following form: (lol I'm just going 2 put this..) A tutor who tought on the flute tried to teach two young tooters to toot. Said the two to the tutor, "Is it harder to toot, or To tutor two tooters to toot?" |