OXFORD DICTIONARY
, n. & v.
--n. (pl. same or beavers)
1 a any large amphibious broad-tailed rodent of the genus Castor, native to N. America, Europe, and Asia, and able to cut down trees and build dams. b its soft light-brown fur. c a hat of this.
2 (in full beaver cloth) a heavy woollen cloth like beaver fur.
3 (Beaver) a boy aged six or seven who is an affiliate member of the Scout Association.
--v.intr. colloq. (usu. foll. by away) work hard.
beaver lamb lamb's wool made to look like beaver fur. eager beaver colloq. an over-zealous person.
, n. hist. the lower face-guard of a helmet.
, n. sl. a bearded man.
20th c.: orig. uncert.
THESAURUS
Vandyke, activist, ball of fire, beard, big-time operator, bristles, bustler, busy bee, doer, down, eager beaver, enthusiast, go-getter, goatee, human dynamo, hustler, imperial, live wire, man of action, man of deeds, militant, new broom, operator, peach fuzz, political activist, powerhouse, side whiskers, stubble, take-charge guy, tuft, wheeler-dealer, whiskers, winner