unconvincing adj. + Add to list US //ˌənkənˈvɪnsɪŋ// UK //ʌnkənvˈɪnsɪŋ// un·con·vinc·ing SynonymsAntonymsEtymology Synonyms flimsyimprobableunbelievableunlikely Antonyms convincingOrigin From un- + convincing.