antiknock

== English == === Alternative forms === anti-knock === Etymology === From anti- +‎ knock. === Pronunciation === === Adjective === antiknock (not comparable) Of an additive added to petroleum/gasoline to reduce the occurrence of engine knock. ==== Translations ==== === Noun === antiknock (plural antiknocks) Such a substance, usually tetraethyl lead (also MMT, MTBE and ethanol). ==== Derived terms ==== ==== Translations ====