ra·​dio | \ ˈrā-dē-ˌō How to pronounce radio (audio) \

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

But Hannity, after discussing the Democratic infighting on Thursday’s show, extended an invitation to her to come on with him on TV sometime for the entire hour or his radio show for three hours., "Alexandria Ocasio-Cortez’s weird week: Blasted on ‘The View,’ gets invite from Sean Hannity," 12 July 2019 The host of a popular radio show started a campaign for contributions. Peter Keough,, "Doc Talk: From an injustice in Georgia to a plea for bees," 11 July 2019 The story was previously the basis for a segment of the radio show This American Life that Wang wrote. Molly Lambert, WSJ, "In Awkwafina’s Drama Debut, Family Matters," 11 July 2019 Learn about all the latest technology on the Kim Komando Show, the nation's largest weekend radio talk show. Kim Komando, USA TODAY, "7 Alexa skills you’ll use time and time again," 11 July 2019 Andrew Greif of the Los Angeles Times covers the Clippers and joined me on the radio show on Monday to talk about the shape-shifting arrival of Kawhi Leonard and Paul George. John Canzano,, "Kawhi Leonard signing helps Clippers shed second-rate image," 8 July 2019 Ramona’s fireworks show is one of just nine in San Diego County simulcast on the radio, said Ramona Rotary President Kim Lasley, noting that the Ramona skyshow will have 921 fireworks synced to the music on KyXy. Ramona Sentinel, "Rotary shifts fireworks campaign into high gear," 27 June 2019 This story was published with PRI's The World, the award-winning public radio show and podcast on global issues, news and insights from BBC, WGBH, PRI, and PRX. Stephen Witt, WIRED, "Fitted With Sensors, Antarctic Seals Track Water Temperatures," 25 June 2019 That same morning Howard Stern interviewed Buress on his radio show, and the shock jock made the most of the controversy to promote Hannibal’s appearance. Longreads, "How the Cosby Story Finally Went Viral — And Why It Took So Long," 7 June 2019

Recent Examples on the Web: Verb

The agent radioed his colleagues to look out for the black BMW, and in a matter of minutes the Marines were pulled over and asked for papers. Meagan Flynn, Anchorage Daily News, "Two active-duty US Marines allegedly smuggled undocumented Mexican immigrants," 9 July 2019 That officer radioed in the car's location and license plate and noticed the car turn onto the street where the crash occurred. Christina Maxouris, CNN, "A 28-year-old Nashville police officer was killed after a teen girl slammed her car into his," 5 July 2019 The officer radioed other officers with a description of the attacker., "Bloody clashes in downtown Portland put police, mayor on defensive," 1 July 2019 Despite his months of simulations, Aldrin didn’t know what this one meant; Armstrong, equally baffled, radioed Mission Control for clarification. Stephen Witt, WIRED, "Apollo 11: Mission Out of Control," 24 June 2019 The paramedics immediately radioed for help from police but wrestled the gun away from the man on their own, according to the Houston Fire Department. Jay R. Jordan, Houston Chronicle, "Houston man opens fire as firefighters try to help him, then tells police he buried body in backyard," 19 June 2019 The timing of Dragonfly’s arrival, in the mid-2030s during Titan’s long northern winter, ruled out a landing near the north pole, home to the moon’s evocative methane seas; those sites would leave it unable to radio home. Paul Voosen, Science | AAAS, "NASA will fly a billion-dollar quadcopter to Titan, Saturn’s methane-rich moon," 27 June 2019 Every 30 minutes, the boats radioed their position to their local operations center in Bahrain. Megan Rose, ProPublica, "Trump Keeps Talking About the Last Military Standoff With Iran — Here’s What Really Happened," 24 June 2019 The Nissan was spotted minutes later on the Dan Ryan, then an officer radioes about a crash at 79th and LaFayette. Madeline Buckley,, "Minister drives by crash scene, not knowing wife died there: 'She was a beautiful, sweet, loving woman'," 11 May 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

Noun and Adjective

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 How to pronounce radio (audio) \
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

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to complain fretfully

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