Worker; set of cards (4)
I believe the answer is:
hand
This clue is a double definition.
'worker' is the first definition.
(I know that hand is a type of jack)
'set of cards' is the second definition.
(I've seen this in another clue)
(Other definitions for hand that I've seen before include "Worker - four inches - bunch of bananas" , "that may be engaged in a shake" , "Clock-pointer" , "Give worker" , "Clock pointer; labourer" .)