Friends married by cleric in reduced expense (9)
I believe the answer is:
compadres
'friends' is the definition.
(I've seen this before)
'married by cleric in reduced expense' is the wordplay.
'married' becomes 'm'.
'by cleric' becomes 'padre' (I've seen this before. I am not sure about the 'by' bit.).
'in' indicates putting letters inside.
'reduced' means to remove the last letter.
'expense' becomes 'cost' (cost is a kind of expense).
'm'+'padre'='mpadre'
'cost' with its final letter removed is 'cos'.
'mpadre' placed within 'cos' is 'COMPADRES'.
(Another definition for compadres that I've seen is " Friends".)