Joke (noun)

1. A remark or story made to provoke laughter or amusement, especially one that is not meant to be taken seriously.
2. An amusing or ridiculous situation or thing.
3. Something that is not meant to be taken seriously or literally.

Origin:

Late middle english: from old french jouste, of unknown origin.

Examples:

1. He told a joke to make the audience laugh.
2. The situation was no joke, it was serious.
3. She didn't think it was a joke when I told her I was leaving.
4. It was a running joke among the employees.
5. He couldn't tell a joke to save his life.