1a member of a confederacy of North American Indian peoples of the north-western plains. The Blackfoot confederacy was made up of three closely related tribes: the Blackfoot proper or Siksika, the Bloods, and the Peigan.
2 [mass noun] the Algonquian language of the Blackfoot, with about 6,000 speakers.
relating to the Blackfoot or their language.
Blackfoot in other Oxford dictionaries
Definition of Blackfoot in the US English dictionary