Definition of mutts:
(n) :
A mongrel dog (or sometimes cat); an animal of mixed breed or uncertain origin.
(n) :
(usually derogatory or humorous) A person of mixed racial or ethnic ancestry.
(n) :
(chiefly US, slang, derogatory) An idiot, a stupid person.
(n) :
(Internet slang, derogatory) A person from the United States, in reference to sense 2.
(n) :
(Antarctica, slang) The snowy sheathbill.
(n) :
Alternative form of matha. [(Hinduism, Jainism) A monastic or similar religious establishment in Hinduism and Jainism, usually more formal and hierarchical than an ashram.]