Long-winged hawk (6)
I believe the answer is:
falcon
'long-winged hawk' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for falcon that I've seen before include "Kind of hunting bird - peregrine is one" , "Long-winged hawk" , "Hunting bird like peregrine or merlin" , "that's seen flying" , "Hunting bird, may be trained" .)