badness n. + Add to list US //ˈbædnəs// UK //bˈædnəs// bad·ness SynonymsAntonymsEtymology Synonyms badmischievousnessnaughtinessseverenessseverity Antonyms goodgoodnessOriginMEbaddenes→ENbadness From Middle English baddenes, badnes, badnesse; equivalent to bad + -ness.