/ Dictionary / Index M mouser: Meaning and Definition of Find definitions for: mous•er Pronunciation: (mou'zur), [key] — n. an animal that catches mice: Our cat is a good mouser. a person or thing that seeks or prowls, as if for prey. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mouser (Thesaurus) mousepox mousetrap Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language