A large aquatic rodent of the genus Castor, having thick brown fur, webbed hind feet, a broad flat tail, and sharp incisors adapted for gnawing bark, felling trees, and constructing dams and underwater lodges. The fur of this rodent. A top hat originally made of the underfur of this rodent. A napped wool fabric, similar to felt, used for outer garments. Vulgar Slang The female genitals. Offensive & Vulgar Slang A woman or girl. Of or relating to a beaver or beavers: beaver fur; a beaver hat. Constructed by beavers: beaver dams. To work diligently and energetically. A piece of armor attached to a helmet or breastplate to protect the mouth and chin. The visor on a helmet.