Cool weapon for group of admirers (3,4)
I believe the answer is:
'group of admirers' is the definition.
(group of fans or admirers)
'cool weapon' is the wordplay.
'cool' becomes 'fan' (I've seen this in another clue).
'weapon' becomes 'club' (weapon for hitting people with).
'for' acts as a link.
(Other definitions for fan club that I've seen before include "Fervent admirers" , "Group devoted to a celebrity" , "Band of followers" , "Association of ardent followers" , "Group of groupies?" .)