Long-eared beast (3)
I believe the answer is:
ass
'long-eared beast' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ass that I've seen before include "Horse relative" , "Hoofed animal, smaller than a horse" , "jack" , "Long-eared animal" , "Donkey or foolish person" .)