Synonyms: flighty, flyaway, head-in-the-clouds, scatterbrained
Definition: guided by whim and fancy
Usage: flighty young girls
Similar words: frivolous
Definition: not serious in content or attitude or behavior
Usage: a frivolous novel; a frivolous remark; a frivolous young woman
Synonyms: scatterbrained, scatty, rattlebrained, rattlepated
Definition: lacking sense or discretion
Usage: his rattlebrained crackpot ideas; how rattlepated I am! I've forgotten what I came for- Glenway Westcott
Similar words: foolish
Definition: devoid of good sense or judgment
Usage: foolish remarks; a foolish decision