[ rey-dee-oh ]
See synonyms for: radioradioedradioingradios on

noun,plural ra·di·os.
  1. wireless telegraphy or telephony: speeches broadcast by radio.

  2. an apparatus for receiving or transmitting radio broadcasts.

  1. a message transmitted by radio.

  1. pertaining to, used in, or sent by radio.

  2. pertaining to or employing radiations, as of electrical energy.

verb (used with object),ra·di·oed, ra·di·o·ing.
  1. to transmit (a message, music, etc.) by radio.

  2. to send a message to (a person) by radio.

verb (used without object),ra·di·oed, ra·di·o·ing.
  1. to transmit a message, music, etc., by radio.

Origin of radio

1910–15; shortening of radiotelegraph or radiotelegraphy

Other words from radio

  • pre·ra·di·o, adjective

Other definitions for radio- (2 of 2)


  1. a combining form with the meanings “dealing with radiant energy” (radiometer), “employing or dealing with radio waves” (radioacoustics; radiolocation; radiotelephone), “emitting rays as a result of the breakup of atomic nuclei” (radioactive; radiocarbon), “characterized by, employing or dealing with such rays” (radiography; radiopaque; radiotherapy).

Origin of radio-

<French, combining form representing Latin radius beam, ray, radius Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use radio in a sentence

  • I am going to get a book about it, and that will tell us just what to do in getting a radio set established.

  • Jessie had noted down the things she thought it would be safe to order before speaking to her father about the radio matter.

  • That afternoon Mr. Norwood brought home the radio receiving set in the automobile.

  • For the next few days Jessie and Amy were busy almost all day long, and evening too, with the radio.

  • She was scared to death that the lightning would strike the house because of the radio aerial.

British Dictionary definitions for radio (1 of 2)


/ (ˈreɪdɪəʊ) /

nounplural -os
  1. the use of electromagnetic waves, lying in the radio-frequency range, for broadcasting, two-way communications, etc

  2. Also called (esp Brit): wireless an electronic device designed to receive, demodulate, and amplify radio signals from sound broadcasting stations, etc

  1. a similar device permitting both transmission and reception of radio signals for two-way communications

  2. the broadcasting, content, etc, of sound radio programmes: he thinks radio is poor these days

    • the occupation or profession concerned with any aspect of the broadcasting of sound radio programmes: he's in radio

    • (modifier) relating to, produced for, or transmitted by sound radio: radio drama

  3. (modifier)

    • of, relating to, employed in, or sent by radio signals: a radio station

    • of, concerned with, using, or operated by radio frequencies: radio spectrum

  4. (modifier) (of a motor vehicle) equipped with a radio for communication: radio car

verb-os, -oing or -oed
  1. to transmit (a message) to (a person, radio station, etc) by means of radio waves

Origin of radio

C20: short for radiotelegraphy

British Dictionary definitions for radio- (2 of 2)


combining form
  1. denoting radio, broadcasting, or radio frequency: radiogram

  2. indicating radioactivity or radiation: radiochemistry; radiolucent

  1. indicating a radioactive isotope or substance: radioactinium; radiothorium; radioelement

Origin of radio-

from French, from Latin radius ray; see radius

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for radio


[ dē-ō ]

  1. The equipment used to generate, alter, transmit, and receive radio waves so that they carry information.

  1. Relating to or involving the emission of radio waves.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.