adjective
- of little value or importance; trifling; trivial
- not properly serious or sensible; silly and light-minded; giddy: a frivolous remark, a frivolous youth
- having no basis in law because of the lack of sound legal arguments, facts, etc. or not brought to court in good faith
Origin:
ME < frivol (< OFr frivole < L frivolus, fragile, silly, akin to friare: see friable) + -ous