/ Dictionary / Index M mutt: Meaning and Definition of Find definitions for: mutt Pronunciation: (mut), [key] — n. Slang. a dog, esp. a mongrel. a stupid or foolish person; simpleton. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mutt (Thesaurus) Mutsuhito Mutt and Jeff Related Content Daily Word Quiz: diligent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language