castor

from The Century Dictionary.

• noun A reddish-brown substance consisting of the preputial follicles of the beaver and their contents, dried and prepared for commercial purposes. It has a strong, penetrating, enduring odor, and was formerly of high repute in medicine, but is now used chiefly by perfumers.
• noun A mineral found in the island of Elba associated with another called pollux.
• noun Glove-leather made from goat-skins. The grain of the skin is removed and it is given a very soft finish, usually gray in color.
• noun See caster, 3.
• noun A beaver.
• noun Among French Canadians, one of the party which called itself the national party, the beaver being the national emblem of Canada.
• noun A genus of sciuromorphic rodent mammals, typical of the family Castoridæ.
• noun A beaver hat; by extension, a silk hat.
• noun A heavy quality of broadcloth used for overcoats.
• Made of beaver-skin or -fur, or of the cloth called beaver.

from the GNU version of the Collaborative International Dictionary of English.

• noun See caster, a small wheel.
• noun (Astron.) the northernmost of the two bright stars in the constellation Gemini, the other being Pollux.
• noun (Min.) A variety of the mineral called petalite, from Elba.
• noun (Zoöl.) A genus of rodents, including the beaver. See beaver.
• noun Castoreum. See Castoreum.
• noun A hat, esp. one made of beaver fur; a beaver.
• noun A heavy quality of broadcloth for overcoats.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A pivoting roller attached to the bottom of furniture to allow it to be moved.
• noun A hat made from the fur of the beaver.
• noun A caster; a container with perforated cap for sprinkling (e.g. pepper-castor).
• noun mineralogy A variety of petalite found in Elba.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a multiple star with 6 components; second brightest in Gemini; close to Pollux
• noun a pivoting roller attached to the bottom of furniture or trucks or portable machines to make them movable
• noun type genus of the Castoridae: beavers
• noun a hat made with the fur of a beaver (or similar material)
• noun a shaker with a perforated top for sprinkling powdered sugar