Support parish priest for keeping it professional (7)
I believe the answer is:
pitprop
'support' is the definition.
(pitprop is a kind of support)
'parish priest for keeping it professional' is the wordplay.
'parish priest' becomes 'pp' (abbreviation for parish priest).
'for keeping' means one lot of letters goes inside another.
'professional' becomes 'pro' (abbreviation).
'it'+'pro'='itpro'
'pp' going around 'itpro' is 'PITPROP'.
(Other definitions for pitprop that I've seen before include "supporter of mine" , "Mine support" , "Mine-working support" .)