Animal that may be XING (4)
I believe the answer is:
deer
'animal that may be xing' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for deer that I've seen before include "Antlered animal" , "Bucks and does?" , "does for example" , "Ruminant(s) -- breed of 13 down" , "Perhaps fallow" .)