knocking
- 01 A2 Elementary
the sound made when someone hits a door or a hard surface with their hand.
the percussive sound produced by striking a surface, typically a door, to attract attention.
Simple“I heard a loud knocking at the front door late last night.”
In context“The persistent knocking at the gate eventually roused the porter, who had fallen asleep during his midnight shift.”
- 02 C1 Advanced
a repetitive metallic sound from an engine that is not working correctly.
a rhythmic metallic sound in an internal combustion engine, often indicating pre-ignition or mechanical wear.
Simple“The mechanic said the knocking in the engine was caused by bad fuel.”
In context“The driver noticed a distinct knocking coming from the cylinder head whenever the vehicle attempted to accelerate up a steep incline.”
UsageOften used as an uncountable noun when referring to the mechanical phenomenon.
Synonymspingingrattle
Usage knocking at the door