Fish of the salmon family (5)
I believe the answer is:
trout
'fish of the salmon family' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for trout that I've seen before include "Tutor (anag.)" , "Tickled fish?" , "unpleasant old woman" , "Rainbow, say" , "tickled to death?" .)