Webster's Revised Unabridged Dictionary · 1913

Dormouse

Dormouse , noun

[Perh. from French dormir to sleep (Prov. English dorm to doze) + English mouse; or perh. changed from French dormeuse, fem., a sleeper, though not found in the sense of a dormouse.]

(Zoology) A small European rodent of the genus Myoxus, of several species. They live in trees and feed on nuts, acorns, etc.; -- so called because they are usually torpid in winter.