Exclusive clubs get rid of head of diversity (6)
I believe the answer is:
closed
'exclusive' is the definition.
(I've seen this before)
'clubs get rid of head of diversity' is the wordplay.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'get rid of' becomes 'lose' (I've seen this in another clue).
'head of' says to take the initial letters.
The first letter of 'diversity' is 'd'.
'c'+'lose'+'d'='CLOSED'
(Other definitions for closed that I've seen before include "Held in private" , "Not open or available to all" , "Terminated" , "See 1" , "successfully completed" .)