Club for a diamond (3)
I believe the answer is:
bat
'club for a diamond' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bat that I've seen before include "Night-flying mammal" , "The cricketer wields it" , "Flutter (eyelids)" , "Nocturnal flier" , "Wooden implement for cricket" .)