/ Dictionary / Index I investigation: Meaning and Definition of Find definitions for: in•ves•ti•ga•tion Pronunciation: (in-ves"ti-gā'shun), [key] — n. the act or process of investigating or the condition of being investigated. a searching inquiry for ascertaining facts; detailed or careful examination. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: investigation (Thesaurus) investigate investigative new drug Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language