quiddity n. + Add to list UK //kwˈɪdɪti// quid·di·ty SynonymsEtymology Synonyms cavilhaecceityquibbleOriginOFRquidité→MEquidite→ENquiddity From Middle English quidite, from Old French quidité, and its source, Late Latin quidditas, from Latin quid (“what”) + -itas (“-ness”).