/ Dictionary / Index O onlooker: Meaning and Definition of Find definitions for: on•look•er Pronunciation: (on'look"ur, ôn'-), [key] — n. spectator; observer; witness. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: onlooker (Thesaurus) on-line catalog onlooking Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language