The Collaborative International Dictionary of English v.0.48:

Beaver \Bea"ver\, n. [OE. bever, AS. beofer, befer; akin to D.
   bever, OHG. bibar, G. biber, Sw. b[aum]fver, Dan. b[ae]ver,
   Lith. bebru, Russ. bobr', Gael. beabhar, Corn. befer, L.
   fiber, and Skr. babhrus large ichneumon; also as an adj.,
   brown, the animal being probably named from its color.
   [root]253. See Brown.]
   [1913 Webster]
   1. (Zool.) An amphibious rodent, of the genus Castor.
      [1913 Webster]

   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.
         [1913 Webster]

   2. The fur of the beaver.
      [1913 Webster]

   3. A hat, formerly made of the fur of the beaver, but now
      usually of silk.
      [1913 Webster]

            A brown beaver slouched over his eyes. --Prescott.
      [1913 Webster]

   4. Beaver cloth, a heavy felted woolen cloth, used chiefly
      for making overcoats.
      [1913 Webster]

   5. A man's beard.
      [PJC]

   6. The hair on a woman's pubic area; -- vulgar. [vulgar
      slang]
      [PJC]

   7. A woman; -- vulgar and offensive. [vulgar slang]
      [PJC]

   8. A person who works enthusiastically and diligently; --
      used especially in the phrase eager beaver. [informal]
      [PJC]

   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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Castor \Cas"tor\, n. [L. castor the beaver, Gr. ?; of uncertain
   origin.]
   1. (Zool.) A genus of rodents, including the beaver. See
      Beaver.
      [1913 Webster]

   2. Castoreum. See Castoreum.
      [1913 Webster]

   3. A hat, esp. one made of beaver fur; a beaver.
      [1913 Webster]

            I have always been known for the jaunty manner in
            which I wear my castor.               --Sir W.
                                                  Scott.
      [1913 Webster]

   4. A heavy quality of broadcloth for overcoats.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Castor \Cast"or\, n.
   See Caster, a small wheel.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Castor \Cas"tor\, n. [L.] (Astron.)
   the northernmost of the two bright stars in the constellation
   Gemini, the other being Pollux.
   [1913 Webster] Castor

The Collaborative International Dictionary of English v.0.48:

Castor \Cas"tor\, Castorite \Cas"tor*ite\, n. [The minerals
   castor and pollux were so named because found together on the
   island of Elba. See Castor and Pollux.] (Min.)
   A variety of the mineral called petalite, from Elba.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Castor
    n 1: a multiple star with 6 components; second brightest in
         Gemini; close to Pollux [syn: Castor, Alpha Geminorum]
    2: a shaker with a perforated top for sprinkling powdered sugar
       [syn: caster, castor]
    3: a pivoting roller attached to the bottom of furniture or
       trucks or portable machines to make them movable [syn:
       caster, castor]
    4: a hat made with the fur of a beaver (or similar material)
       [syn: beaver, castor]
    5: type genus of the Castoridae: beavers [syn: Castor, genus
       Castor]

U.S. Gazetteer Places (2000):

Castor, LA -- U.S. village in Louisiana
   Population (2000):    209
   Housing Units (2000): 101
   Land area (2000):     1.197188 sq. miles (3.100703 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    1.197188 sq. miles (3.100703 sq. km)
   FIPS code:            13260
   Located within:       Louisiana (LA), FIPS 22
   Location:             32.252757 N, 93.164933 W
   ZIP Codes (1990):     71016
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Castor, LA
    Castor