Breadcrumb Home > Thesaurus > O Synonyms of off key Find synonyms for: Adjective 1. false, off-key, sour, inharmonious (vs. harmonious), unharmonious usage: 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: umbrage Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language