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Definition of octane number
: a number that is used to measure the antiknock properties of a liquid motor fuel (such as gasoline) with a higher number indicating a smaller likelihood of knocking
— called also octane rating
— compare cetane numberKeep scrolling for more
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Merriam-Webster unabridgedWords at Play
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Time Traveler for octane number
The first known use of octane number was in 1931
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