The Collaborative International Dictionary of English v.0.48:

Carlock \Car"lock\, n. [F. carlock, fr. Russ. Karl['u]k'.]
   A sort of Russian isinglass, made from the air bladder of the
   sturgeon, and used in clarifying wine.
   [1913 Webster]

U.S. Gazetteer Places (2000):

Carlock, IL -- U.S. village in Illinois
   Population (2000):    456
   Housing Units (2000): 197
   Land area (2000):     0.243612 sq. miles (0.630953 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.243612 sq. miles (0.630953 sq. km)
   FIPS code:            11215
   Located within:       Illinois (IL), FIPS 17
   Location:             40.581951 N, 89.132613 W
   ZIP Codes (1990):     61725
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Carlock, IL
    Carlock