Hawk eating head of raw fish (5)
I believe the answer is:
trout
'fish' is the definition.
(trout is a kind of fish)
'hawk eating head of raw' is the wordplay.
'hawk' becomes 'tout' (I've seen this before).
'eating' means one lot of letters goes inside another.
'head of' says to take the initial letters.
The first letter of 'raw' is 'r'.
'tout' placed around 'r' is 'TROUT'.
(Other definitions for trout that I've seen before include "air" , "Tasty fish, brown or rainbow" , "Prized river fish" , "bad-tempered woman" , "Catch" .)