Hawk biting head of raw fish (5)
I believe the answer is:
trout
'fish' is the definition.
(trout is a kind of fish)
'hawk biting head of raw' is the wordplay.
'hawk' becomes 'tout' (I've seen this before).
'biting' indicates putting letters inside (some letters bite or swallow others).
'head of' indicates taking the first letters.
The initial letter of 'raw' is 'r'.
'tout' placed around 'r' is 'TROUT'.
(Other definitions for trout that I've seen before include "tickled to death?" , "bad-tempered woman" , "grumpy old woman" , "Food fish" , "air" .)