- any of 18 isomeric saturated hydrocarbons having the formula C8H18, some of which are obtained in the distillation and cracking of petroleum.
- octane number.
- a liquid alkane hydrocarbon found in petroleum and existing in 18 isomeric forms, esp the isomer n -octane. Formula: C 8 H 18See also isooctane
n.hydrocarbon of the methane series, 1872, coined from octo- (see octa-) + -ane; so called because it has eight carbon atoms. A fuel’s octane rating, in reference to its anti-knocking quality, is attested from 1932.
- Any of several hydrocarbons having eight carbon atoms connected by single bonds. It is commonly added to gasoline to prevent knocking from uneven burning of fuel in internal-combustion engines. Octane is the eighth member of the alkane series. Chemical formula: C8H18.