Navajo or Hopi (5)
I believe the answer is:
tribe
'navajo or hopi' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tribe that I've seen before include "Clannish group" , "Ethnic grouping" , "Group of related people" , "Israelites' division" , "Extended family group" .)