Rough rows in church (6)
I believe the answer is:
coarse
'rough' is the definition.
('coarse' can be similar in meaning to 'rough')
'rows in church' is the wordplay.
'rows' becomes 'oars' (I've seen this before).
'in' means one lot of letters goes inside another.
'church' becomes 'ce' (abbreviation for Church of England).
'oars' going inside 'ce' is 'COARSE'.
(Other definitions for coarse that I've seen before include "gross" , "Rough, harsh" , "Boorish" , "Rude, vulgar" , "needing refinement" .)