Synonyms of scatterbrained

Adjective

1. rattlebrained, rattlepated, scatterbrained, scatty, foolish (vs. wise)

usage: lacking sense or discretion; "his rattlebrained crackpot ideas"; "how rattlepated I am! I've forgotten what I came for"- Glenway Westcott

2. flighty, flyaway, head-in-the-clouds, scatterbrained, frivolous (vs. serious)

usage: guided by whim and fancy; "flighty young girls"