playfulness vs frivolousness

playfulness and frivolousness both are nouns.

Word	Noun	Adjective	Verb	Adverb
playfulness	Yes	No	No	No
frivolousness	Yes	No	No	No

As nouns, frivolousness is a hypernym of playfulness; that is, frivolousness is a word with a broader meaning than playfulness:

Other hypernyms of playfulness include frivolity.

playfulness (noun)	frivolousness (noun)
activities that are enjoyable or amusing	the trait of being frivolous; not serious or sensible
a disposition to find (or make) causes for amusement
a festive merry feeling