Pre-conquest Andean (4)
I believe the answer is:
inca
'pre-conquest andean' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for inca that I've seen before include "Andean culture" , "An old Peruvian like Cain" , "Member of old South American Indian people of Peru" , "Pre-conquest South American people" , "mountain dweller" .)