Definition of over the air in US English:

over the air

adverb

  • By means of radio or television broadcast; (now frequently) specifically by the transmission of radio signals broadcast through the earth's atmosphere (as distinct from cable transmission); over the airwaves.

adjective

  • Usually with hyphens. Of, involving, or by means of radio or television broadcasting, especially as distinct from cable transmission.

Origin

1920s. From over + the + air. Compare slightly later on the air.

Pronunciation

over the air

/ˌəʊvə ðɪ ˈɛː/