An amusing story.

Something said or done for amusement, not in seriousness.

“It was a joke!”

The root cause or main issue, especially an unexpected one

To do or say something for amusement rather than seriously.

“I didn’t mean what I said — I was only joking.”

(intransitive, followed by with) To dupe in a friendly manner for amusement; to mess with, play with.

“Relax, man, I'm just joking with you.”

To make merry with; to make jokes upon; to rally.

“to joke a comrade”