Cutting maple branch is complicated to start with (7)
I believe the answer is:
acerbic
'cutting' is the definition.
(I've seen this before)
'maple branch is complicated to start with' is the wordplay.
'maple' becomes 'acer' (I've seen this before).
'to start with' indicates taking the first letters.
The initial letters of 'branch is complicated' is 'bic'.
'acer'+'bic'='ACERBIC'
(Other definitions for acerbic that I've seen before include "Sour in taste or harsh in tone" , "Tasting sour or caustic in speech" , "Sharp, forthright" , "Bitter in taste -- harsh in tone" , "Bitter, sour" .)