Trim, as branches (5)
I believe the answer is:
prune
'trim as branches' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for prune that I've seen before include "Dull person" , "Shrivelled fruit" , "Cut back the dried plum" , "Trim - dried fruit" , "Trim (tree); dried plum" .)