Powerful feller Bond saw (8)
I believe the answer is:
chainsaw
'powerful feller' is the definition.
(something which might fell trees)
'bond saw' is the wordplay.
'bond' becomes 'chain' (chain is a kind of bond).
'chain'+'saw'='CHAINSAW'
(Other definitions for chainsaw that I've seen before include "woodcutter?" , "Texas massacre tool" , "powered device" , "Tree-lopper's tool" , "Timber cutter" .)