One reeks spilling fuel (8)
I believe the answer is:
kerosene
'fuel' is the definition.
(kerosene is a kind of fuel)
'one reeks spilling' is the wordplay.
'spilling' indicates anagramming the letters.
'one'+'reeks'='onereeks'
'onereeks' anagrammed gives 'KEROSENE'.
(Other definitions for kerosene that I've seen before include "Oil used as fuel in lamps and heaters" , "No seeker for American fuel oil" , "Paraffin oil (E, not I)" , "Combustible" , "Sore knee (anag.)" .)