Take a bough? (3)
I believe the answer is:
'take a bough?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lop that I've seen before include "Chop (off)" , "Hack" , "Prune, cut the top off" , "Cut away branches or twigs" , "Remove branches from a tree" .)