Webster's Revised Unabridged Dictionary · 1913

Frivolous

Frivolous , adjective

[Latin frivolus; prob. akin to friare to rub, crumble, English friable: compare French frivole.]

1.
Of little weight or importance; not worth notice; slight; as, a frivolous argument. — Swift
2.
Given to trifling; marked with unbecoming levity; silly; interested especially in trifling matters.
His personal tastes were low and frivolous. — Macaulay