MUSS INFORMAL, Meaning of MUSS INFORMAL, in English muss informal,chiefly N. Amer.■ verb make untidy or messy. ■ noun a mess or muddle.Derivativesmussy adjective OriginC19: appar. a var. of mess . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004