/ Dictionary / Index I impostor: Meaning and Definition of Find definitions for: im•pos•tor Pronunciation: (im-pos'tur), [key] — n. a person who practices deception under an assumed character, identity, or name. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: impostor (Thesaurus) impost block imposture Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language