Definition of "castor"

A hat made from the fur of the beaver.  quotations  examples

A heavy quality of broadcloth for overcoats.  examples

Castoreum (bitter exudate of mature beavers).  examples

Any of various nymphalid butterflies of the genus Ariadne, of Africa and Asia.  examples

(mineralogy) A variety of petalite found in Elba.  examples

(especially UK) Alternative spelling of caster, especially in its senses

1. A pivoting roller attached to the bottom of furniture to allow it to be moved.  examples

2. A container with a perforated cap for sprinkling its contents, especially salt, pepper, etc.  quotations  examples

   Quotations

   • Mrs. Hussey soon appeared, with a mustard-pot in one hand and a vinegar-cruet in the other, having just broken away from the occupation of attending to the castors, and scolding her little black boy meantime.

     1851 November 14, Herman Melville, “The Ramadan”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, page 92