/ Thesaurus / O Synonyms of off key Find synonyms for: Adjective1. false, off-key, sour, inharmonious (vs. harmonious), unharmonioususage: inaccurate in pitch; "a false (or sour) note"; "her singing was off key"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language