Upset angry God (4)
I believe the answer is:
eros
'god' is the definition.
(Eros is an example)
'upset angry' is the wordplay.
'upset' shows that the letters should be reversed in order.
'angry' becomes 'sore' (similar in meaning).
'sore' in reverse letter order is 'EROS'.
(Other definitions for eros that I've seen before include "Group of instincts" , "Winged archer" , "God of love; life instinct (Freud)" , "One worshipped" , "Cupid, to the Greeks" .)