| Octane (n.) Any one of a group of metametric hydrocarcons (C8H18) of the methane series. The most important is a colorless, volatile, inflammable liquid, found in petroleum, and a constituent of benzene or ligroin. Thesaurus Entries alcohol, benzine, briquette, burnable, butane, carbon, charcoal, coal, coke, combustible, dope, ethane, ethanol, fireball, firing, flammable, flammable material, fuel, fuel additive, fuel dope, gas, gas carbon, gasoline, heptane, hexane, inflammable, inflammable material, isooctane, jet fuel, kerosene, methane, methanol, natural gas, oil, paraffin, peat, pentane, propane, propellant, rocket fuel, turf |