airspace

noun5

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.

   • Various European countries transferred the aviation control of their adjoining airspace to Eurocontrol, while each retaining legal jurisdiction.
2. •
   That part of the sky designated for the sole use of aircraft.
3. •
   The portion of an enclosed area which contains air, especially breathable air.
4. •
   The cavity in a cavity wall containing air for insulation.
5. •
   Space (i.e. a few neighboring frequencies) available for broadcasting within a particular frequency band.

   • The legalisation of free radios caused a bitter fight for airspace.