Bea·ver n.
 1. Zool. An amphibious rodent, of the genus Castor.
 Note: ☞ It has palmated hind feet, and a broad, flat tail. It is remarkable for its ingenuity in constructing its lodges or “houses,” and dams across streams.  It is valued for its fur, and for the material called castor, obtained from two small bags in the groin of the animal.  The European species is Castor fiber, and the American is generally considered a variety of this, although sometimes called Castor Canadensis.
 2. The fur of the beaver.
 3. A hat, formerly made of the fur of the beaver, but now usually of silk.
    A brown beaver slouched over his eyes.   --Prescott.
 4. Beaver cloth, a heavy felted woolen cloth, used chiefly for making overcoats.
 Beaver rat Zool., an aquatic ratlike quadruped of Tasmania (Hydromys chrysogaster).
 Beaver skin, the furry skin of the beaver.
 Bank beaver. See under 1st Bank.