air vs air space

air and air space both are nouns.

Word	Noun	Adjective	Verb	Adverb
air	Yes	No	Yes	No
air space	Yes	No	No	No

air (noun)	air space (noun)
travel via aircraft	the space in the atmosphere immediately above the earth
a distinctive but intangible quality surrounding a person or thing
a succession of notes forming a distinctive sequence
medium for radio and television broadcasting
the region above the ground
the mass of air surrounding the Earth
a slight wind (usually refreshing)
a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of
once thought to be one of four elements composing the universe (Empedocles), associated with the humour blood

air (verb)	air space (verb)
expose to cool or cold air so as to cool or freshen
expose to warm or heated air, so as to dry
make public
broadcast over the airwaves, as in radio or television
be broadcast
expose to fresh air