This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. The time during which a radio or television station is broadcasting. Also called airspace.

n. The time at which a radio or television program is broadcast.

n. The duration during which a radio or television program (or part of one) is transmitted.

n. The chargeable use of a mobile phone, either in minutes or in units dependent on the use or traffic.

n. The period during which a person riding a rollercoaster or similar ride experiences a feeling of weightlessness.

"The easiest way to fill space or airtime is to give it over to advocates on particular issues -- to substitute opinion for reporting."

airspace   

3rd-party    value-added    applications    quiet    dangerousness