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

See also: frivolous

• Yehudi Menuhin
• Yekaterinoslav
• yell
• yelled
• yeller
• yelling
• yellow
• yellow adder's tongue
• yellow ageratum
• yellow asphodel
• yellow avens
• yellow bachelor's button
• yellow bass
• yellow bean
• yellow bedstraw
• yellow bells
• yellow berry
• yellow bile
• yellow birch
• yellow bone marrow
• yellow bristlegrass
• yellow bugle
• yellow bunting
• yellow card
• yellow cattley guava