Noun:
1: merriment, fun, playfulness activities that are enjoyable or amusing; "I do it for the fun of it"; "he is fun to have around"
2: sport, play, fun 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"
3: fun violent and excited activity; "she asked for money and then the fun began"; "they began to fight like fun"
4: playfulness, fun a disposition to find (or make) causes for amusement; "her playfulness surprised me"; "he was fun to be with"
Adjective:
1: entertaining, amusive, fun, diverting, amusing providing enjoyment; pleasantly entertaining; "an amusing speaker"; "a diverting story"; "a fun thing to do"