Definition of "airspace"

airspace

noun
countable and uncountable, plural airspaces
1. (politics, aviation) 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.
  Quotations
  Haines has previous experience of dealing with a hugely disruptive crisis. He said: "I left the railway in 2008 and went to the Civil Aviation Authority. And within a few months I was in the middle of an Icelandic volcanic storm. Eyafjallajokull closed airspace across northern Europe.
  2020 March 25, “Network News: Railway working with government to combat crisis”, in Rail, page 7
2. (aviation) that part of the sky designated for the sole use of aircraft.
3. (broadcasting) Space (i.e. a few neighboring frequencies) available for broadcasting within a particular frequency band.
4. The portion of an enclosed area which contains air, especially breathable air.
5. (construction) The cavity in a cavity wall containing air for insulation.