playfulness (
http://definr.com/playfulness)
n 1: a festive merry feeling [syn:
gaiety]
2: a disposition to find (or make) causes for amusement; "her
playfulness surprised me"; "he was fun to be with" [syn:
fun]
3: activities that are enjoyable or amusing; "I do it for the
fun of it"; "he is fun to have around" [syn:
fun,
merriment]