Club's male champion (4)
I believe the answer is:
mace
'club's' is the definition.
(thesaurus)
'male champion' is the wordplay.
'male' becomes 'm' (common abbreviation).
'champion' becomes 'ace' (I've seen this before**).
'm'+'ace'='MACE'
(Other definitions for mace that I've seen before include "Came to get ceremonial staff" , "Tear gas - spice" , "something fragrant" , "Disabling spray" , "Came to find ceremonial staff" .)