Wrong American gets a hole in the head (5)
I believe the answer is:
sinus
'a hole in the head' is the definition.
(I've seen this before)
'wrong american' is the wordplay.
'wrong' becomes 'sin' (I've seen this before).
'american' becomes 'us' (abbreviation for United States).
'sin'+'us'='SINUS'
'gets' acts as a link.
(Other definitions for sinus that I've seen before include "Cavity within a bone" , "Air-filled cavity of the skull" , "Nasal cavity" , "snotty enclosure" , "Channel between brain and skull" .)