Fuel that man would cut (6)
I believe the answer is:
gashed
'cut' is the definition.
('gashed' can be a synonym of 'cut')
'fuel that man would' is the wordplay.
'fuel' becomes 'gas' (gas is a kind of fuel).
'that man' becomes 'he'.
'would' becomes 'd' (I've seen this in other clues).
'gas'+'he'+'d'='GASHED'
(Other definitions for gashed that I've seen before include "Wounded" , "Cut open" , "Deeply cut" .)