The Collaborative International Dictionary of English v.0.48:

Creeks \Creeks\ (kr[=e]ks), n. pl.; sing. Creek. (Ethnol.)
   A tribe or confederacy of North American Indians, including
   the Muskogees, Seminoles, Uchees, and other subordinate
   tribes. They formerly inhabited Georgia, Florida, and
   Alabama.
   [1913 Webster]