fun | ja

fun (fn)
n.
1. A source of enjoyment, amusement, or pleasure.
2. Enjoyment; amusement: have fun at the beach.
3. Playful, often noisy, activity.
intr.v. funned, fun·ning, funs Informal
To behave playfully; joke.
adj. Informal
Enjoyable; amusing: "You're a real fun guy" (Margaret Truman).
Idiom:
for/in fun
As a joke; playfully. .