'Frivolity' definitions:

Definition of 'frivolity'

From: WordNet
noun
The trait of being frivolous; not serious or sensible [syn: frivolity, frivolousness] [ant: earnestness, serious-mindedness, seriousness, sincerity]
noun
Something of little value or significance [syn: bagatelle, fluff, frippery, frivolity]
noun
Acting like a clown or buffoon [syn: buffoonery, clowning, japery, frivolity, harlequinade, prank]

Definition of 'Frivolity'

From: GCIDE
  • Frivolity \Fri*vol"i*ty\, n.; pl. Frivolities. [Cg. F. frivolit['e]. See Frivolous.] The condition or quality of being frivolous; also, acts or habits of trifling; unbecoming levity of disposition. [1913 Webster]