antiknocking

8.2

Able to stop the knocking noise in a car engine when fuel burns

adjective
/ˌæntiˈnɑkɪŋ/

Specialized

: antiknocking

Using antiknocking substances can help prevent damage to the engine.

Examples

The mechanic recommended an antiknocking fuel to improve engine performance.
For high-performance cars, it's essential to use antiknocking agents in the fuel.
The site processed tetraethyl lead, an antiknocking additive for gasoline.

Academic text (1995)

Synonyms

antiknock

vsantiknocking

Specialized

1 8.1

That stops engine knocking in gasoline engines

is the same meaning but expressed with an -ing form

Antonyms

knocking

37 2.2

A sharp repeated sound from a door or machine when parts hit each other

Surface Forms

antiknocking positive

Morphology

antiknocking = knocking (semi-transparent) = anti + knock + ing

The form clearly means 'anti-' plus 'knocking', but the relevant engine sense of 'knocking' is specialized, so the meaning is not fully obvious to an average learner.

Etymology

The word antiknocking starts with anti- meaning 'against' and uses knock, which is the sharp 'knock' or 'ping' sound an engine makes when it runs badly. So, antiknocking is used for fuels or additives that work 'against' that bad engine noise and help the engine run smoothly.