Son of God is intrinsically American (7)
I believe the answer is:
perseus
'son of god' is the definition.
(son of Zeus)
'intrinsically american' is the wordplay.
'intrinsically' becomes 'per se' (synonyms).
'american' becomes 'us' (abbreviation for United States).
'perse'+'us'='PERSEUS'
'is' acts as a link.
(Other definitions for perseus that I've seen before include "Greek hero who rescued Andromeda" , "Mythical hero" , "Hero who killed Medusa" , "Medusan killer" , "Group of stars" .)