[an-tee-nok, an-tahy-, an-tee-nok, an-tahy-]
such a substance added to fuel in an internal-combustion engine.
Origin of antiknock
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a compound, such as lead tetraethyl, added to petrol to reduce knocking in the engine
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