Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “knock”


noun [C]     /nɒk/
NOISE a sudden short noise made when something or someone hits a surface: a knock at/on the doorSounds made by objects, movement or impact
HIT a hit, sometimes causing damage or injury: a knock on the headHitting against objects accidentally and colliding
(Definition of knock noun from the Cambridge Learner's Dictionary © Cambridge University Press)

Definitions of “knock” in other dictionaries

Word of the Day

work out

to exercise in order to improve the strength or appearance of your body

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More