Church lies about implement (6)
I believe the answer is:
'implement' is the definition.
(chisel is a kind of implement)
'church lies about' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'about' indicates anagramming the letters.
'lies' anagrammed gives 'isel'.
(Other definitions for chisel that I've seen before include "Wood-shaping tool" , "Sculptor's tool" , "Carpenter's or mason's tool" , "Slangily cheat with wood-working tool" , "Carpentry tool" .)