Adjective: frivolous fri-vu-lus
- Not serious in content, attitude or behaviour
"a frivolous young woman"; "a frivolous novel"; "a frivolous remark"
See also: airheaded [informal], dippy [informal], dizzy, earnestness, empty-headed, featherbrained, flighty, flippant, flyaway, giddy, head-in-the-clouds [informal], idle, light, lightheaded, light-headed, light-minded, scatterbrained, serious-mindedness, seriousness, silly, sincerity, superficial, trivial
Antonym: serious