Meaning of “joke” - Learner’s Dictionary

joke

noun uk us /dʒəʊk/

B1 [ C ] something that someone says to make people laugh, usually a short story with a funny ending:

to tell/make a joke
a good joke about dogs
be a joke informal

to not be serious or not deserve respect:

The investigation was a joke.
be no joke

to be serious or difficult:

It's no joke driving on icy roads.
take a joke

to understand and accept a trick without becoming angry or upset

→ See also practical joke

(Definition of “joke noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)