Gasoline or kerosene (4)
I believe the answer is:
fuel
This clue is a double definition.
'gasoline' is the first definition.
(thesaurus)
'kerosene' is the second definition.
(thesaurus)
(Other definitions for fuel that I've seen before include "Material fed to flames" , "Substance burned to source power" , "Gas, oil or petrol, for instance" , "Combustibles" , "Eg, coal or oil" .)