friv·o·lous 
(frĭvə-ləs)
(frĭvə-ləs)adj.
1. Unworthy of serious attention; trivial: a frivolous novel.
2. Inappropriately silly: a frivolous purchase.
[Middle English, probably from Latin frīvolus, of little value, probably from friāre, to crumble.]
frivo·lous·ly adv.
frivo·lous·ness n.