Start chopping a tree for money (4)
I believe the answer is:
cash
'for money' is the definition.
(cash is a type of money)
'start chopping a tree' is the wordplay.
'start' indicates taking the first letters.
'a tree' becomes 'ash' (ash is a kind of tree).
The initial letter of 'chopping' is 'c'.
'c'+'ash'='CASH'
(Other definitions for cash that I've seen before include "Till" , "Funds" , "Hard currency" , "Spondulicks" , "Wimbledon champion" .)