1. Lacking seriousness; given to frivolity
   - airheaded, dizzy, featherbrained, giddy, light-headed, lightheaded, silly

See also: frivolous

• Y-fronts
• Y-linked gene
• Y-shaped
• Y2K
• Y2K compliant
• ya
• yabber
• yacca
• yacca podocarp
• yacht
• yacht chair
• yacht club
• yacht race
• yachting
• yachting cap
• yachtsman
• yachtswoman
• yack
• yack away
• yacker
• yackety-yak
• yaffingale
• yaffle
• Yafo
• yagi