Definition of "Mouse" :

noun: any of numerous small rodents typically resembling diminutive rats having pointed snouts and small ears on elongated bodies with slender usually hairless tails

noun: a hand-operated electronic device that controls the coordinates of a cursor on your computer screen as you move it around on a pad; on the bottom of the device is a ball that rolls on the surface of the pad

"A mouse takes much more room than a trackball."

noun: person who is quiet or timid

noun: a swollen bruise caused by a blow to the eye

verb: manipulate the mouse of a computer

verb: to go stealthily or furtively