Main entry: flighty, flyaway, head-in-the-clouds, scatterbrained
Definition: guided by whim and fancy
Usage: flighty young girls
Main entry: 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