Club in hand is cosh (5)
I believe the answer is:
disco
'club' is the definition.
(night club)
'in hand is cosh' is the wordplay.
'in' indicates the answer is hidden within the clue.
'DISCO' can be found hidden inside 'hand is cosh'.
(Other definitions for disco that I've seen before include "Party with music" , "Modern dancehall of youth" , "party for dancers" , "Demonic spirit" , "Thumping music" .)