1. Something that is silly, clownish, and not serious: As long as it lasted, they wined and dined with happy frivolity.
2. Thoughtlessness or irresponsibility: Earl's mother couldn't understand the frivolity of his behavior.
3. Foolish behavior or actions; the state of being trivial and unimportant: Helena spends a lot of money on the latest fashions and other frivolities.
4. Etymology: from Latin: frivolus, "silly, empty, trifling"; from friare, "to break, to rub away, to crumble".