airspace

1. A specified portion of the atmosphere, especially that under the technical aviation control and/or jurisdiction of a particular state over which territory (and territorial waters) it lies. (countable, uncountable) · Holonym: aerospace (not synonymous)
2. That part of the sky designated for the sole use of aircraft. (countable, uncountable)
3. Space (i.e. a few neighboring frequencies) available for broadcasting within a particular frequency band. (countable, uncountable) · The legalisation of free radios caused a bitter fight for airspace.
4. The portion of an enclosed area which contains air, especially breathable air. (countable, uncountable)
5. The cavity in a cavity wall containing air for insulation. (countable, uncountable)

Plural airspaces