deer mouse

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A North American mouse (Peromyscus maniculatus) having white feet and underparts, and a long, bicolored tail.

Century Dictionary and Cyclopedia

1. n. A common name of the American jumping-mouse, Zapus hudsonius, the only member of the family Zapodidæ (which see): so called from its agility. It is a species about 4 inches long, with a longer scaly tail and enlarged hind quarters and hind feet, by means of which it clears several feet at a bound. The color is yellowish brown, darker on the back and paler below. It is generally distributed in woodland of the United States and British America.
2. n. A popular name of several species of true mice indigenous to North America, of the family Muridœ and genus Hesperomys. It is especially applied to the common white-footed mouse (H. leucopus), which is of a grayish or yellowish-brown color above, with snow-white under parts and paws, and the tail bicolored. It is about 3½ inches long, the tail less, and is very generally distributed in North America.

GNU Webster's 1913

1. n. (Zoöl.) the white-footed mouse (Peromyscus leucopus, formerly Hesperomys leucopus) of America.

WordNet 3.0

1. n. brownish New World mouse; most widely distributed member of the genus