The Collaborative International Dictionary of English v.0.48:

Santees \San`tees"\, n. pl.; sing. Santee. (Ethnol.)
   One of the seven confederated tribes of Indians belonging to
   the Sioux, or Dakotas.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Santee
    n 1: a member of the eastern branch of the Sioux [syn: Santee,
         Santee Sioux, Santee Dakota, Eastern Sioux]
    2: the Siouan language spoken by the Santee

U.S. Gazetteer Places (2000):

Santee, NE -- U.S. village in Nebraska
   Population (2000):    302
   Housing Units (2000): 116
   Land area (2000):     0.563031 sq. miles (1.458243 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.563031 sq. miles (1.458243 sq. km)
   FIPS code:            43475
   Located within:       Nebraska (NE), FIPS 31
   Location:             42.838711 N, 97.853188 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Santee, NE
    Santee


U.S. Gazetteer Places (2000):

Santee, CA -- U.S. city in California
   Population (2000):    52975
   Housing Units (2000): 18833
   Land area (2000):     16.059137 sq. miles (41.592972 sq. km)
   Water area (2000):    0.219917 sq. miles (0.569583 sq. km)
   Total area (2000):    16.279054 sq. miles (42.162555 sq. km)
   FIPS code:            70224
   Located within:       California (CA), FIPS 06
   Location:             32.848237 N, 116.988249 W
   ZIP Codes (1990):     92071
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Santee, CA
    Santee


U.S. Gazetteer Places (2000):

Santee, SC -- U.S. town in South Carolina
   Population (2000):    740
   Housing Units (2000): 394
   Land area (2000):     2.014088 sq. miles (5.216465 sq. km)
   Water area (2000):    0.014937 sq. miles (0.038686 sq. km)
   Total area (2000):    2.029025 sq. miles (5.255151 sq. km)
   FIPS code:            63790
   Located within:       South Carolina (SC), FIPS 45
   Location:             33.478405 N, 80.484581 W
   ZIP Codes (1990):     29142
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Santee, SC
    Santee