What is the meaning of Mouse?

Any one of numerous species of small rodents belonging to the genus Mus and various related genera of the family Muridae. The common house mouse (Mus musculus) is found in nearly all countries. The American white-footed, or deer, mouse (Hesperomys leucopus) sometimes lives in houses. See Dormouse, Meadow mouse, under Meadow, and Harvest mouse, under Harvest.

Source: Webster’s Revised Unabridged Dictionary (1913), via OPTED