ˈkīˌ(y)üs, ̷ ̷ˈ ̷ ̷ noun
( plural cayuse or cayuses )
1. usually capitalized
a. : a Waiilatpuan people of Washington and Oregon
b. : a member of such people
2. : the language of the Cayuse people
3. plural cayuses , West : a native range horse ; especially : indian pony — compare bronco , mustang