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octane

[ok-teyn]
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noun Chemistry.
  1. any of 18 isomeric saturated hydrocarbons having the formula C8H18, some of which are obtained in the distillation and cracking of petroleum.
  2. octane number.
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Origin of octane

First recorded in 1870–75; oct- + -ane
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for octane

Historical Examples

  • Less than 10 years later octane ratings had increased to over 100, putting the diesel at a further disadvantage.

    The First Airplane Diesel Engine: Packard Model DR-980 of 1928

    Robert B. Meyer


British Dictionary definitions for octane

octane

noun
  1. 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
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for octane

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.

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Online Etymology Dictionary, © 2010 Douglas Harper

octane in Science

octane

[ŏktān′]
  1. 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.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.