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

See also: frivolous

• conation
• conative
• conatus
• concatenate
• concatenation
• concave
• concave lens
• concave polygon
• concave polyhedron
• concave shape
• concavely
• concaveness
• concavity
• concavo-concave
• concavo-convex
• conceal
• concealable
• concealed
• concealer
• concealing
• concealment
• concede
• conceding
• conceit
• conceited