Stiffener for leading player going to church (6)
I believe the answer is:
starch
'stiffener' is the definition.
(starch is used to make fabric stiff)
'leading player going to church' is the wordplay.
'leading player' becomes 'star' (I've seen this in another clue).
'going to' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation).
'star'+'ch'='STARCH'
'for' is the link.
(Other definitions for starch that I've seen before include "It stiffens shirts and collars" , "Formality - give stiffness" , "Setter" , "ceremony" , "Stiffening preparation used in laundering" .)