Untouchable dad gets hair back! (6)
I believe the answer is:
pariah
'untouchable' is the definition.
(I've seen this before)
'dad gets hair back' is the wordplay.
'dad' becomes 'pa' (both can mean one's father).
'gets' is a charade indicator (letters next to each other).
'back' is a reversal indicator.
'hair' back-to-front is 'riah'.
'pa'+'riah'='PARIAH'
(Other definitions for pariah that I've seen before include "Outcast (state)" , "Person despised and avoided" , "someone socially unacceptable" , "Outcast (dog)" , "Unacceptable person" .)