The Collaborative International Dictionary of English v.0.48:

Gasoline \Gas"o*line\, Gasolene \Gas"o*lene\(? or ?; 104), n.
   A highly volatile mixture of fluid hydrocarbons, obtained
   mostly from petroleum, as also by the distillation of
   bituminous coal. It is used as a fuel for most automobiles
   and for many other vehicles with internal combustion engines.
   The gasoline of commerce is typically blended with additives
   to improve its performance in internal combustion engines.
   Gasoline was also used in the early 1900's in making air gas,
   and in giving illuminating power to water gas. See
   Carburetor.

   Syn: petrol[Brit]. [1913 Webster +PJC] Gasoline engine

WordNet (r) 3.0 (2006):

gasoline
    n 1: a volatile flammable mixture of hydrocarbons (hexane and
         heptane and octane etc.) derived from petroleum; used
         mainly as a fuel in internal-combustion engines [syn:
         gasoline, gasolene, gas, petrol]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "gasoline":
   alcohol, avgas, benzine, briquette, burnable, butane, carbon,
   charcoal, coal, coal oil, coke, combustible, crude, crude oil,
   dope, electricity, ethane, ethanol, ethyl, ethyl gas, fireball,
   firing, flammable, flammable material, fossil oil, fuel,
   fuel additive, fuel dope, gas, gas carbon, heptane, hexane,
   high-octane gas, high-test, illuminant, illuminating gas,
   inflammable, inflammable material, isooctane, jet fuel, kerosene,
   lead-free gas, light source, low-lead gas, luminant, methane,
   methanol, motor oil, natural gas, octane, oil, paraffin, peat,
   pentane, petrol, petroleum, premium gas, propane, propellant,
   regular, rock oil, rocket fuel, turf