[bea.ver] n, pl beavers [ME bever, fr. OE beofor; akin to OHG bibar beaver, and prob. to OE brun brown--more at brown] (bef. 12c) 1 or pl beaver a: either of two large semiaquatic herbivorous rodents (Castor canadensis of No. America and C. fiber of Eurasia) having webbed hind feet and a broad flat scaly tail and constructing dams and partially submerged lodges b: the fur or pelt of the beaver
2. a: a hat made of beaver fur or a fabric imitation b: silk hat
3: a heavy fabric of felted wool or of cotton napped on both sides
4: the pudenda of a woman--usu. considered vulgar
[2]beaver n [ME baviere, fr. MF] (15c) 1: a piece of armor protecting the lower part of the face
2: a helmet visor [3]beaver vi (1946): to work energetically "~ing away at the problem"