adj, noun ·3 syllables ·Rare ·Advanced level

Definitions

Noun

1. 1
   Such a substance, usually tetraethyl lead (also MMT, MTBE and ethanol).
2. 2
   any of various compounds that are added to gasoline to reduce engine knocking wordnet

Adjective

1. 1
   Of an additive added to petroleum/gasoline to reduce the occurrence of engine knock. not-comparable

Adjective

1. 1
   suppressing or eliminating engine knock in combustion engines wordnet

Synonyms

All synonyms

antiknockingantiknockingcushiondampdampergag

Etymology

From anti- + knock.

Related phrases

anti-knock indexengine knocktetraethyl lead

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.