Church manses converted for bishop, say (8)
I believe the answer is:
chessman
'bishop say' is the definition.
(bishop is a kind of chessman)
'church manses converted' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'converted' indicates anagramming the letters.
'manses' with letters rearranged gives 'essman'.
'ch'+'essman'='CHESSMAN'
'for' acts as a link.
(Other definitions for chessman that I've seen before include "that's played on board" , "Playing piece" , "Eg, bishop, knight" , "Eg, bishop or rook" , "queen, perhaps" .)