Any of numerous small rodents of the families Muridae and Cricetidae, such as the common house mouse (Mus musculus), characteristically having a pointed snout, small rounded ears, and a long naked or almost hairless tail.
Any of various similar or related animals, such as the jumping mouse, the vole, or the jerboa.
A cowardly or timid person.
Informal A discolored swelling under the eye caused by a blow; a black eye.
Computer Science A hand-held, 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.