Winged horse (7)
I believe the answer is:
pegasus
'winged horse' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pegasus that I've seen before include "Fish" , "Immortal winged horse of Greek mythology" , "group of stars" , "Constellation in the northern hemisphere near Andromeda and Pisces" , "Winged horse - constellation" .)