“+ 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