The Collaborative International Dictionary of English v.0.48:

Busby \Bus"by\ (b[u^]z"b[y^]), n.; pl. Busbies (b[i^]z).
   (Mil.)
   A military headdress or cap, used in the British army. It is
   of fur, with a bag, of the same color as the facings of the
   regiment, hanging from the top over the right shoulder.
   [1913 Webster]

WordNet (r) 3.0 (2006):

busby
    n 1: tall hat; worn by some British soldiers on ceremonial
         occasions [syn: bearskin, busby, shako]

U.S. Gazetteer Places (2000):

Busby, MT -- U.S. Census Designated Place in Montana
   Population (2000):    695
   Housing Units (2000): 201
   Land area (2000):     14.197736 sq. miles (36.771966 sq. km)
   Water area (2000):    0.049094 sq. miles (0.127152 sq. km)
   Total area (2000):    14.246830 sq. miles (36.899118 sq. km)
   FIPS code:            11200
   Located within:       Montana (MT), FIPS 30
   Location:             45.527535 N, 106.973707 W
   ZIP Codes (1990):     59016
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Busby, MT
    Busby