castor 1
/kas"teuhr, kah"steuhr/ , n.
1. Also, castoreum . a brownish, unctuous substance with a strong, penetrating odor, secreted by certain glands in the groin of the beaver, used in medicine and perfumery.
2. a hat made of beaver or rabbit fur.
3. a heavy woolen cloth used mainly for coats.
4. a beaver.
[ 1350-1400; ME kástor beaver ]
castor 2
/kas"teuhr, kah"steuhr/ , n.
caster (defs. 2-5).