Cut fuel coming to hospital (4)
I believe the answer is:
gash
'cut' is the definition.
(I've seen this before)
'fuel coming to hospital' is the wordplay.
'fuel' becomes 'gas' (gas is a kind of fuel).
'coming to' is a charade indicator (letters next to each other).
'hospital' becomes 'h'.
'gas'+'h'='GASH'
(Other definitions for gash that I've seen before include "Unnecessary" , "Deep open cut" , "Long deep cut" , "Laceration" , "Open wound" .)