airspace

/EH1 R S P EY0 S/
noun
  1. 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. 2

    That part of the sky designated for the sole use of aircraft.

  3. 3

    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.

  4. 4

    The portion of an enclosed area which contains air, especially breathable air.

  5. 5

    The cavity in a cavity wall containing air for insulation.

Source: https://en.wiktionary.org/wiki/airspace