General English

  • noun a method of sending out and receiving messages using air waves
  • noun a machine which sends out and receives messages using air waves


  • noun wireless transmission through space of electromagnetic waves in the approximate frequency range from 10 kHz to 300,000 MHz


  • (written as radio-)
    A prefix denoting concepts pertaining to radiant energy, or its uses. For example, radiometer.
  • (written as radio-)
    A prefix denoting radioactive, or pertaining to radioactivity. For instance, radionuclide.
  • The transmission and/or reception of information, such as voice, video, data, or control signals, in which there are no connecting wires. Instead, such communication is achieved by means of electromagnetic waves, such as radio waves or infrared waves, or via acoustic waves. Also, the specific content.
  • The broadcasting of signals which are intended for reception by a radio receiver.
  • Abbreviation of radio frequency. Same as RF.

Information & Library Science

  • noun equipment used to broadcast speech, sounds and data over long distances
  • noun the method of broadcasting to the public using this equipment

Media Studies

  • noun radio broadcasting as an industry or profession
  • noun sound broadcasts transmitted by means of radio waves
  • noun the broadcasting by radio of programmes for the public
  • noun a station which transmits radio broadcasts, or an organisation involved in radio broadcasting
  • noun an electronic device for receiving sound broadcasts transmitted via radio signals


  • prefix
    (written as radio-)
    referring to radiation
  • prefix
    (written as radio-)
    referring to radioactive substances
  • prefix
    (written as radio-)
    referring to the radius in the arm


  • noun the transmission and reception of audible signals, using electromagnetic waves
  • noun an apparatus designed to transmit and receive radio signals


  • noun a system for sending out or receiving messages using atmospheric waves, or an apparatus which does this
  • verb to send a message using a radio

Origin & History of “radio”

Radio began life, in the first decade of the 20th century, as an abbreviation of radiotelegraphy, a compound based on Latin radius. this originally meant ‘staff, stake’, but it is its secondary meanings that have contributed significantly to English: ‘spoke of a wheel’, for instance, lies behind English radius (16th c.), and the notion of a ‘ray’ has produced radiant (15th c.), radiate (17th c.), radium (19th c.) (etymologically a metal emitting ‘rays’), and indeed ray. Radiotelegraphy itself denoted the sending of messages by electromagnetic ‘rays’. Radar (20th c.), coined in the USA in 1941, is an acronym formed from radio detection and ranging.