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.
See More

Recent Examples on the Web: Noun

Epstein’s death was quickly seized on by an editor for conservative news website The Blaze, conservative radio hosts, a Florida Republican party official and a Trump appointee, all of whom sought to connect the suicide to the Clinton family. NBC News, "After Epstein's suicide, conspiracy theories flourish online," 10 Aug. 2019 She’s taken me out on every one of her tours prior to me having any singles on the radio. Alison Abbey, Woman's Day, "Reba McEntire, Miranda Lambert and Carly Pearce Dish on the Sisterhood of Country Music," 9 Aug. 2019 McConnell, who has strongly opposed background checks in the past, made his remarks in an interview with a Kentucky radio host, Terry Meiners of WHAS in Louisville. Maggie Haberman,, "214 mayors, including Boston’s Walsh, call on Senate to reconvene and pass background check bills," 8 Aug. 2019 Hopefully the radio host and columnist will be able to leverage that experience into some quality starts for the media team at Coors Field. Kyle Newman, The Denver Post, "Rockies Insider: Imagining the lineup for a Colorado media baseball team," 8 Aug. 2019 The radio host said that Washington Redskins quarterback Dwayne Haskins is more his style of player. Jeremy Cluff, azcentral, "Kyler Murray slammed by Colin Cowherd: 'Dwayne Haskins is the future, not Kyler Murray'," 8 Aug. 2019 DeMaio, a conservative radio host, is the fifth Republican to enter the race for Hunter’s seat but is so far the only one who carries significant name recognition. San Diego Union-Tribune, "Carl DeMaio announces challenge for Rep. Duncan Hunter’s congressional seat," 5 Aug. 2019 Besides, what’s the point of a discussion about race in America that only involves white TV pundits, columnists and radio hosts? Ruben Navarrette Jr., The Mercury News, "Navarrette: America’s dialogue on race is now a vexing monologue," 27 July 2019 Before his interview with Democratic presidential candidate Pete Buttigieg, veteran country radio host Blair Garner reportedly sent a letter to his affiliate stations, warning them more or less not to lose their minds over the booking. Michael Arceneaux, Essence, "Opinion: Pete Buttigieg Will Have To Deal With Homophobia In Every Community, Not Just The Black One," 24 July 2019

Recent Examples on the Web: Verb

The pilot radioed the tarmac to report the incident, according to the airline. Bukola Adebayo, CNN, "Man jumps on plane wing as it prepares for takeoff," 19 July 2019 Fallon plays the Dustin in all this, radioing over to Colbert, our Suzie of this sketch, to wish him good luck on his late-night talk show return. Nick Romano,, "Jimmy Fallon, Stephen Colbert recreate NeverEnding Story moment from Stranger Things," 16 July 2019 The cost may be worth it if the next-generation minefield can also radio back when it’s been tampered with or when a mine has detonated. Kyle Mizokami, Popular Mechanics, "The U.S. Army Is Building a Smarter Land Mine," 16 July 2019 Relyea stepped back and radioed in that the man had a knife and asking for additional units, the report read. Nicholas Rondinone,, "Danbury officer, under investigation for police shooting this month, cleared in deadly 2018 shooting," 12 July 2019 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

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.

See More

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

Keep scrolling for more

Learn More about radio

Statistics for radio

Look-up Popularity

Time Traveler for radio

The first known use of radio was in 1887

See more words from the same year

Keep scrolling for more

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

Keep scrolling for more

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 usually brief trip or an expedition

Get Word of the Day daily email!

Test Your Vocabulary

Summer 2019 Words of the Day Quiz

  • a-bowl-of-peach-sorbet-with-cut-peaches-next-to-it
  • Which is a synonym of desideratum?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!