Father's upset, hurt by Native American (6)
I believe the answer is:
apache
'native american' is the definition.
(group of Native American tribes)
'father's upset hurt by' is the wordplay.
'father' becomes 'pa' (pa can mean dad or father).
'upset' is a reversal indicator.
'hurt' becomes 'ache' (synonyms).
'by' says to put letters next to each other.
'pa' backwards is 'ap'.
'ap'+'ache'='APACHE'
(Other definitions for apache that I've seen before include "American speech" , "Indians" , "American Indian - French gangster" , "on the streets of Paris" , "ruffian in capital of France" .)