1. lacking in seriousness
1. The vast majority of Bollywood films are utterly frivolous.
2. self-indulgently carefree
2. Can't you take anything seriously, you frivolous idiot?
3. relatively unimportant
3. His account of the events is basically correct: he's only left out a few frivolous details.
frivolus (silly, empty, trifling, worthless) (Latin)
Fri-vo-lous ~Free - If something is free, u don't take it seriously, you think oh they are giving it for free coz its not that important stuff. or not the stuff in demand. or not the stuff taken seriously by public. Fri+vol+ous = Free+Will ->one who acts with his own will, carefree, not serious.