Hound's prey (4)
I believe the answer is:
hare
'hound's prey' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hare that I've seen before include "Sort of rabbit" , "Fast-running mammal" , "Rabbit-like animal" , "animal running in fields" , "Old saying: 'Let the .... sit" .)