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

See also: frivolous

• acetic acid
• acetic anhydride
• acetify
• acetin
• aceto-
• acetoacetic acid
• acetone
• acetone body
• acetonemia
• acetonic
• acetonuria
• acetophenetidin
• acetose
• acetous
• acetphenetidin
• acetum
• acetyl
• acetyl chloride
• acetyl group
• acetyl radical
• acetylate
• acetylation
• acetylcholine
• acetylene
• acetylenic