Breadcrumb Home > Dictionary > Index W wacko: Meaning and Definition of Find definitions for: wack•o Pronunciation: (wak'ō), [key] — n., pl. adj. wack•os, —n. an eccentric, strange, or odd person. —adj. wacky. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: wacko (Thesaurus) wacked-out wacky TrendingHere are the facts and trivia that people are buzzing about. The Book of Philippians: Summary Current Events This Week: May 2023 Preamble of the United Nations Charter Queen Victoria Books of the Bible: New Testament Books in Order The 88 Recognized Constellations ✖ Related Content Daily Word Quiz: miasma Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language