- intention: That upon which the mind is set.
- interact: To act reciprocally.
- intercede: To mediate between persons.
- intercept: To interrupt the course of.
- intercession: Entreaty in behalf of others.
- intercessor: A mediator.
- interdict: Authoritative act of prohibition.
- interim: Time between acts or periods.
- interlocutor: One who takes part in a conversation or oral discussion.
- interlude: An action or event considered as coming between others of greater length.
- intermediate: Being in a middle place or degree or between extremes.
- interminable: Having no limit or end.
- intermission: A recess.
- intermit: To cause to cease temporarily.
- intermittent: A temporary discontinuance.
- interpolation: Verbal interference.
- interpose: To come between other things or persons.
- interposition: A coming between.
- interpreter: A person who makes intelligible the speech of a foreigner by oral translation.
- interrogate: To examine formally by questioning.
- interrogative: Having the nature or form of a question.
- interrogatory: A question or inquiry.
- interrupt: To stop while in progress.
- intersect: To cut through or into so as to divide.
- intervale: A low tract of land between hills, especially along a river.
- intervene: To interfere for some end.
- intestacy: The condition resulting from one's dying not having made a valid will.
- intestate: Not having made a valid will.
- intestine: That part of the digestive tube below or behind the stomach, extending to the anus.
- intimacy: Close or confidential friendship.
- intimidate: To cause to become frightened.
- intolerable: Insufferable.
- intolerance: Inability or unwillingness to bear or endure.
- intolerant: Bigoted.
- intoxicant: Anything that unduly exhilarates or excites.
- intoxicate: To make drunk.
- intracellular: Occurring or situated within a cell.
- intramural: Situated within the walls of a city.
- intrepid: Fearless and bold.
- intricacy: Perplexity.
- intricate: Difficult to follow or understand.
- intrigue: A plot or scheme, usually complicated and intended to accomplish something by secret ways.
- intrinsic: Inherent.
- introductory: Preliminary.
- introgression: Entrance.
- intromit: To insert.
- introspect: To look into.
- introspection: The act of observing and analyzing one's own thoughts and feelings.
- introversion: The act of turning or directing inward, physically or mentally.
- introvert: To turn within.