fun, merriment, playfulness -- (activities that are enjoyable or amusing; "I do it for the fun of it"; "he is fun to have around")
fun, play, sport -- (verbal wit or mockery (often at another's expense but not to be taken seriously); "he became a figure of fun"; "he said it in sport")
fun -- (violent and excited activity; "she asked for money and then the fun began"; "they began to fight like fun")
playfulness, fun -- (a disposition to find (or make) causes for amusement; "her playfulness surprised me"; "he was fun to be with")