Definition of "Fun" :

noun: activities that are enjoyable or amusing

"I do it for the fun of it."

noun: violent and excited activity

"She asked for money and then the fun began."

noun: a disposition to find (or make) causes for amusement

"He was fun to be with."

noun: verbal wit or mockery (often at another's expense but not to be taken seriously)

"He became a figure of fun."