/ Dictionary / Index I imbecile: Meaning and Definition of Find definitions for: im•be•cile Pronunciation: (im'bu-sil, -sul or, esp. Brit., -sēl"), [key] — n. a person of the second order in a former classification of mental retardation, above the level of idiocy, having a mental age of seven or eight years and an intelligence quotient of 25 to 50. a dunce; blockhead; dolt. —adj. mentally feeble. showing mental feebleness or incapacity. stupid; silly; absurd. weak or feeble. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: imbecile (Thesaurus) imbalance imbecilic Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language