Swing jester? (3)
I believe the answer is:
wag
I believe this is a double definition.
'swing' is the first definition.
(thesaurus)
'jester?' is the second definition.
(I've seen this in another clue)
(Other definitions for wag that I've seen before include "Wave to and fro, as a dog's tail" , "Jocular person" , "Comedian" , "He must be joking" , "Accompanying lovely" .)