Ascend, lopping first branch (4)

I believe the answer is:
limb
'branch' is the definition.
(I've seen this in other clues)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for limb that I've seen before include "Eg, arm, leg" , "Arm, leg or wing" , "Branch - member" , "Eg wing" , "as part of plane, say" .)