Resident of old Peru (4)
I believe the answer is:
inca
'resident of old peru' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for inca that I've seen before include "Ancient South American" , "Early Peruvian" , "Member of ancient Peruvian tribe" , "Ancient civilisation of Peru" , "Pyramid builders" .)