ra·​dio | \ˈrā-dē-ˌō \

Definition of radio 

(Entry 1 of 4)

1 : of, relating to, or operated by radiant energy

2 : of or relating to electric currents or phenomena (such as electromagnetic radiation) of frequencies between about 3000 hertz and 300 gigahertz

3a : of, relating to, or used in radio or a radio set

b : specializing in radio or associated with the radio industry

c(1) : transmitted by radio

(2) : making or participating in radio broadcasts

d : controlled or directed by radio


plural radios

Definition of radio (Entry 2 of 4)

1a : the wireless transmission and reception of electric impulses or signals by means of electromagnetic waves

b : the use of these waves for the wireless transmission of electric impulses into which sound is converted

2 : a radio message

3 : a radio receiving set

4a : a radio transmitting station

b : a radio broadcasting organization

c : the radio broadcasting industry

d : communication by radio


radioed; radioing; radios

Definition of radio (Entry 3 of 4)

transitive verb

1 : to send or communicate by radio

2 : to send a radio message to

intransitive verb

: to send or communicate something by radio

Definition of radio- (Entry 4 of 4)

— see radi-

Examples of radio in a Sentence


The news was sent by radio. I listen to the radio all the time. I heard the news on the radio. There's a problem with the car's radio. The radio was playing very loudly. The pilot's radio wasn't working.


The police radioed for backup. The stranded sailors were radioing for help. The pilot radioed in to the control tower. The police radioed a report back to the station. They radioed the Coast Guard for help.
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Recent Examples on the Web: Noun

Apple Music users will be able to ask Alexa to play favorite songs, artists, and albums, as well as any of the streaming service’s curated playlists and radio stations. James Vincent, The Verge, "Apple Music is coming to Echo devices next month," 30 Nov. 2018 But still, it wasn't interpreted that way by some: Regardless if Bobby was feeling bitter or not, the radio personality is going through to the next week. Kayla Keegan, Good Housekeeping, "'Dancing With the Stars' Bobby Bones Threw MAJOR Shade at Alexis Ren and Other Contestants," 23 Oct. 2018 Joe Walsh, the former Republican congressman turned TV and radio personality, said in a series of Twitter posts late Tuesday and early Wednesday that he, too, had been deceived by Mr. Cohen’s show. Alex Marshall, New York Times, "Sarah Palin Says She Was ‘Duped’ by Sacha Baron Cohen," 11 July 2018 One Chicago radio personality is hoping to turn his storage locker fees into treasures for fans. Jennifer Johnson,, "Memorabilia, merchandise and 'regular junk:' Steve Dahl to host garage sale at Des Plaines casino," 6 July 2018 Alex Holley of Fox29’s Good Day Philadelphia and WDAS radio personality Frankie Darcell served as the night’s hosts, both appropriately and coincidentally dressed in flowing orange dresses. Brandon T. Harden,, "Jill Scott, Boyz II Men deliver sizzling homecoming performances at WDAS Summer Block Party," 1 July 2018 Mark Simone, a radio personality, said the Red Hen's refusal of service shows inconsistency with Democrats' stance on immigration. Ben Tobin, USA TODAY, "Donald Trump, Sarah Sanders, Red Hen set Twitter abuzz," 25 June 2018 No one should be confusing us with a radio station in North Carolina any longer! Lindsey Tramuta, Condé Nast Traveler, "Innovators: KLM CEO Pieter Elbers on Keeping Up With the 'Big Kids'," 11 Oct. 2018 Kennedy said his firm will conduct its own investigation into what caused the blasts, according to WBUR radio. Fox News, "Columbia Gas customers file class-action lawsuit over Boston-area explosions, fires," 19 Sep. 2018

Recent Examples on the Web: Verb

Then there’s the design, which employs a stem much like Apple’s AirPods — that should help keep an uninterrupted connection by pushing the wireless radios further away from the listener’s ear. Vlad Savov, The Verge, "RHA’s TrueConnect buds look like a promising AirPods rival," 4 Oct. 2018 The wranglers could radio to each other, but otherwise our communications would be limited to yelling across the plain. Ella Riley-adams, Vogue, "I Ditched My Phone for a Montana Cattle Drive (and Finally Dealt With My Feelings)," 3 Oct. 2018 Their mission is to blow up a key transmitter so German forces can’t radio in a warning about the big attack. Bryan Bishop, The Verge, "Overlord is a gloriously entertaining piece of B-movie schlock," 9 Nov. 2018 He and another staffer secured themselves in a safe building and radioed zoo staff. Kevin Mcgill, The Seattle Times, "Sharp teeth: Jaguar may have bitten through steel cable," 17 July 2018 Miles radioed to warn others of the discovery, likely saving hundreds of lives, but was never heard from again, his sister said. Julia Terruso,, "After Trump-Kim summit, Philly-area family asking 'What about my brother' could finally get an answer," 20 June 2018 Craig Chapman radioed the Sky Harbor tower, asking for police backup. Ashleigh R Wilson, azcentral, "Yes, it really happened on an airport tarmac in metro Phoenix," 29 July 2016 However, the No. 2 Ford struggled on a long green-flag run late in the race and fell two laps behind after radioing in that something broke in his suspension. Fox News, "Kyle Busch wins rain-delayed Bristol NASCAR race," 16 Apr. 2018 Politi said the most common way for sharks to be detected along the Cape is by spotters in planes who radio the sightings to the various harbor masters, who then relay the news to on-duty lifeguards and beach patrol personnel. Sophia Eppolito And Marek Mazurek,, "On the Cape, tourists and locals take sharks in stride," 9 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radio.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of radio


1887, in the meaning defined at sense 1


1903, in the meaning defined at sense 1a


1913, in the meaning defined at transitive sense 1

History and Etymology for radio


radio entry 2 or radio-


short for radiotelegraphy

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Statistics for radio

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Time Traveler for radio

The first known use of radio was in 1887

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More Definitions for radio



English Language Learners Definition of radio

 (Entry 1 of 2)

: the system or process that is used for sending and receiving signals through the air without using wires

: programs that are broadcast by radio

: a device that is used to receive the signals that are broadcast by radio



English Language Learners Definition of radio (Entry 2 of 2)

: to send a message to someone by radio


ra·​dio | \ˈrā-dē-ˌō \
plural radios

Kids Definition of radio

 (Entry 1 of 3)

1 : the process that is used for sending or receiving signals by means of electromagnetic waves without a connecting wire

2 : a device that receives signals sent by radio

3 : programs that are broadcast by radio

4 : a device used to both send and receive messages by radio

5 : the radio broadcasting industry



Kids Definition of radio (Entry 2 of 3)

1 : of or relating to radio waves

2 : of, relating to, or used in radio broadcasting


radioed; radioing

Kids Definition of radio (Entry 3 of 3)

: to communicate or send a message to by radio

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More from Merriam-Webster on radio

Rhyming Dictionary: Words that rhyme with radio

Spanish Central: Translation of radio

Nglish: Translation of radio for Spanish Speakers

Britannica English: Translation of radio for Arabic Speakers Encyclopedia article about radio

Comments on radio

What made you want to look up radio? Please tell us where you read or heard it (including the quote, if possible).


a soft lustrous wool fabric with mohair

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