The Collaborative International Dictionary of English v.0.48:

Calamus \Cal"a*mus\, n.; pl. Calami. [L., a reed. See Halm.]
   1. (Bot.) The indian cane, a plant of the Palm family. It
      furnishes the common rattan. See Rattan, and Dragon's
      blood.
      [1913 Webster]

   2. (Bot.) A species of Acorus (Acorus calamus), commonly
      called calamus, or sweet flag. The root has a pungent,
      aromatic taste, and is used in medicine as a stomachic;
      the leaves have an aromatic odor, and were formerly used
      instead of rushes to strew on floors.
      [1913 Webster]

   3. (Zool.) The horny basal portion of a feather; the barrel
      or quill.
      [1913 Webster]

WordNet (r) 3.0 (2006):

calamus
    n 1: any tropical Asian palm of the genus Calamus; light tough
         stems are a source of rattan canes
    2: the aromatic root of the sweet flag used medicinally
    3: perennial marsh plant having swordlike leaves and aromatic
       roots [syn: sweet flag, calamus, sweet calamus, myrtle
       flag, flagroot, Acorus calamus]
    4: a genus of Sparidae [syn: Calamus, genus Calamus]
    5: the hollow spine of a feather [syn: quill, calamus,
       shaft]

Easton's 1897 Bible Dictionary:

Calamus
   the Latin for cane, Hebrew _Kaneh_, mentioned (Ex. 30:23) as one
   of the ingredients in the holy anointing oil, one of the sweet
   scents (Cant. 4:14), and among the articles sold in the markets
   of Tyre (Ezek. 27:19). The word designates an Oriental plant
   called the "sweet flag," the Acorus calamus of Linnaeus. It is
   elsewhere called "sweet cane" (Isa. 43:24; Jer. 6:20). It has an
   aromatic smell, and when its knotted stalk is cut and dried and
   reduced to powder, it forms an ingredient in the most precious
   perfumes. It was not a native of Palestine, but was imported
   from Arabia Felix or from India. It was probably that which is
   now known in India by the name of "lemon grass" or "ginger
   grass," the Andropogon schoenanthus. (See CANE.)


U.S. Gazetteer Places (2000):

Calamus, IA -- U.S. city in Iowa
   Population (2000):    394
   Housing Units (2000): 173
   Land area (2000):     0.487306 sq. miles (1.262116 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.487306 sq. miles (1.262116 sq. km)
   FIPS code:            09820
   Located within:       Iowa (IA), FIPS 19
   Location:             41.826669 N, 90.759793 W
   ZIP Codes (1990):     52729
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Calamus, IA
    Calamus