antiknock
an-ti-knock
noun
A substance added to petrol to prevent engine knocking.
"Modern petrol contains antiknock additives for smoother running."
Thesaurus
Synonyms: antiknocking, leaded
an-ti-knock
A substance added to petrol to prevent engine knocking.
"Modern petrol contains antiknock additives for smoother running."
Synonyms: antiknocking, leaded