The portion of an enclosed area which contains air, especially breathable air.
that part of the sky designated for the sole use of aircraft.
The cavity in a cavity wall containing air for insulation.
Space (i.e. a few neighboring frequencies) available for broadcasting within a particular frequency band.
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.
An unoccupied area or volume.
Vacuum; a space containing nothing at all
An unoccupied space where something may be stored
A feeling of longing for someone or something that is gone; a sense of a thing's absence.