to knock
- verb
- /nɑk/
- Specialized
- The mechanic explained that the unusual knock in the engine was due to premature ignition.
He he added Tetra ethyl lead the scamp as patron discovered it reduced knocking on heaven's door.
- He he added Tetra ethyl lead the scamp as patron discovered it reduced knocking on heaven's door.
Examples
-
I felt like I'd had all the wind knocked out of me.
Fiction book (1997) -
So lead was added to fuel to to make engines more efficient, to knock less and to to make them less prone to breakdown.
-
Suddenly, the engine starts knocking violently and the car dies.
Fiction book (1994) -
If overdone, hard playing will knock the pans out of tune.
Academic text (1995) -
The lifters knock louder as she eases off the gas, rolling into Wild Horse.
Fiction book (1999) -
Using higher quality fuel can help reduce engine knock and improve performance.
-
If your car starts to knock, it may be an indication that you need to check the fuel mixture.
Synonyms
To make a metallic knocking sound in an engine when fuel burns too early
To make a knocking sound in an engine when fuel burns too early
Idioms
- Informal
To defeat the person or team at the top and take their place
- Offensive
To hit someone very hard or to shock someone very much
Phrasal Verbs
- Offensive
To make someone start thinking and behaving reasonably, often by scolding or force
- UK
To make something quickly and simply from things you have, like a shelter or meal
Compounds
- Jargon
The illegal action of hitting the ball forward with the hand or arm while trying to catch it
- Jargon
A rummy game where a player ends a round if unmatched cards total less than ten points
How Severe
Surface Forms
Etymology
Knock for an engine sound is also from the same simple idea — the engine makes a sharp, knocking noise, so mechanics call that problem 'knock' or 'knocking'.