n. pl.   mice (m
īs)
 1. a.  Any of numerous small rodents of the families Muridae and Cricetidae, such as the house mouse, characteristically having a pointed snout, small rounded ears, and a long naked or almost hairless tail.
b.  Any of various similar or related animals, such as the jumping mouse, the vole, or the jerboa.
 2.  A cowardly or timid person.
3.  Informal   A discolored swelling under the eye caused by a blow; a black eye.
4. pl.   mice or  mous·es (mousĭz)  Computers   A handheld, button-activated input device that when rolled along a flat surface directs an indicator to move correspondingly about a computer screen, allowing the operator to move the indicator freely, as to select operations or manipulate text or graphics.