antiknock

[ an-tee-nok, an-tahy-, an-tee-nok, an-tahy- ]

adjective

1. noting or pertaining to a substance, as tetraethyllead or ferrocene, used as a fuel additive for an internal-combustion engine to eliminate or minimize knock.

noun

1. such a substance added to fuel in an internal-combustion engine.

antiknock

/ ˌæntɪˈnɒk /

noun

1. a compound, such as lead tetraethyl, added to petrol to reduce knocking in the engine

Word History and Origins

Origin of antiknock¹

First recorded in 1920–25; anti- + knock

Example Sentences

Modern engines not only don’t need lead but have sophisticated antiknock technologies that sense a fuel’s octane rating and adjust their ignition timing to prevent damage.

From New York Times

Water injection made another appearance in one of the first turbocharged production cars, the 1962 Oldsmobile Cutlass Turbo Jetfire, where, instead of the sophisticated antiknock sensors that are standard equipment in modern cars, a mixture of water and methanol was added to the air-fuel mixture to control combustion.

From New York Times

The new fuel can be used in any car with a low-compression engine not requiring the antiknock properties of leaded gas.

From Time Magazine Archive

In 1962, with his two sons, Gottwald bought Ethyl Corp., the world's largest producer of lead antiknock compounds for gasoline.

From Time Magazine Archive

Since leaded antiknock compounds accounted for 36% of those sales and a hefty 60% of the profits, Ethyl may have more knocks ahead.

From Time Magazine Archive