/ Dictionary / Index N nincompoop: Meaning and Definition of Find definitions for: nin•com•poop Pronunciation: (nin'kum-pp", ning'-), [key] — n. a fool or simpleton. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: nincompoop (Thesaurus) niña* nine Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language