un·defined \“+\adjective Etymology:un- (I) + defined, past participle of define 1.: not defined : not precisely limited, determined, or distinguished : vague < some undefined sense of excitement — W.H.Wright > 2.: not capable of being described or limited in words : primitive < undefined term > < undefined concept > • un·de·fined·ly\-nə̇dlē, -nd-\adverb • un·de·fined·ness\-nə̇dnə̇s, -n(d)nə̇s\noun-es