Donkey's need, in a party game (4)
I believe the answer is:
tail
'donkey's need in a party game' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tail that I've seen before include "Follow (a suspect)" , "that can be cast by a lizard" , "Last, rear, part" , "Feebler batsmen" , "Follow - train" .)