Hawk circles river for fish (5)
I believe the answer is:
trout
'for fish' is the definition.
(trout is a kind of fish)
'hawk circles river' is the wordplay.
'hawk' becomes 'tout' (both can mean to sell something).
'circles' indicates putting letters inside.
'river' becomes 'r' (abbreviation for river).
'tout' going around 'r' is 'TROUT'.
(Other definitions for trout that I've seen before include "Tasty fish, brown or rainbow" , "tickled to death?" , "one often tickled?" , "Small salmonlike fish" , "Food fish" .)