octane number: Meaning and Definition of

oc'tane num"ber

Pronunciation: [key]
  1. (of gasoline) a designation of antiknock quality, numerically equal to the percentage of isooctane by volume in a mixture of isooctane and normal heptane that matches the given gasoline in antiknock characteristics. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.