MUTT Meaning of MUTT in English n. 25B6; noun (informal)a long-haired mutt : MONGREL, hound, dog, cur; Austral. informal mong, bitzer. he pitied the poor mutt. : See fool noun sense 1. Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012