japery vs frivolity

japery and frivolity both are nouns.

Word	Noun	Adjective	Verb	Adverb
japery	Yes	No	No	No
frivolity	Yes	No	No	No

As nouns, japery and frivolity are synonyms defined as:

Other synonyms of japery include buffoonery, clowning, harlequinade, prank.

japery (noun)	frivolity (noun)
acting like a clown or buffoon	acting like a clown or buffoon
	something of little value or significance
	the trait of being frivolous; not serious or sensible