Related Clues:

• Option in some new autos
• Hang in the breeze
• Melody
• Part of A.F.B.
• It may be hot, thin or cold
• Word with horn or filter
• Simple song
• O
• Make public
• Oxygen source
• Balloon filler
• See 34-Down
• It's mostly nitrogen
• Travel method
• Epitome of lightness