Cut when working (4)
I believe the answer is:
hewn
'cut' is the definition.
('hewn' can be a synonym of 'cut')
'when working' is the wordplay.
'working' is an anagram indicator.
'when' anagrammed gives 'HEWN'.
(Other definitions for hewn that I've seen before include "Cut with an axe or chisel" , "Sculpted" , "Cut with blows" , "(Of wood) cut, chopped" , "Cut - carved - chopped" .)