Caddo
noun
Cad·do ˈka-(ˌ)dō 
1
plural Caddo or Caddos : a member of a nation of Indigenous peoples of Louisiana, Arkansas, Oklahoma, and eastern Texas
2
: the language of the Caddo peoples
Word History
Etymology
American French Cadaux, modification of American Spanish Cadojodacho, from Caddo kaduhdá·čuʔ, a Caddo tribe
First Known Use
1805, in the meaning defined at sense 1