noun
antiknock agent
Technical term used in automotive and fuel chemistry to refer to additives that reduce engine knocking.
ガソリンにアンチノック剤を添加することで、エンジンのノッキングを防ぐことができる。
By adding an antiknock agent to gasoline, engine knocking can be prevented.
ノッキング is the engine knocking phenomenon itself, while アンチノック剤 is the additive used to prevent it.
Compound of the English loanword アンチノック (antiknock) and 剤 (ざい, 'agent, chemical').