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.
See More

Recent Examples on the Web: Noun

An additional $250,000 of the funding will be allocated for public education, including television and radio spots in both English and Spanish. Bree Burkitt, azcentral, "Latest string of deadly pedestrian accidents continues Arizona trend," 2 July 2018 Freelance members work in screen, television and new media, while staff members work in electronic news media — television, radio and digital news shops. Jonathan Handel, The Hollywood Reporter, "WGA East Unveils Board Candidates Ahead of Election," 27 June 2018 So, here is the genesis of that case of mistaken identity: Villanova coach Jay Wright has weekly television and radio shows, like most big-time college coaches. Jr Radcliffe, Milwaukee Journal Sentinel, "Where did DiVincenzo's 'Michael Jordan of Delaware' nickname come from?," 22 June 2018 The policy allows directors of newspapers, television and radio stations to put out news of important events like fatal disasters without awaiting the previously mandatory authorization from the Communist Party's Department of Ideology. Andrea Rodriguez, The Christian Science Monitor, "Cuba loosens grip on media, allows for more independent reporting," 21 June 2018 Freedom Partners, the organization that coordinates the network’s political activities, is launching television and radio ad campaigns, which will run in the Washington D.C. market and national conservative talk programs, respectively. Alana Abramson, Time, "Koch Brothers' Groups Are Lobbying Congress to Curb President Trump's Authority on Tariffs," 20 June 2018 Turn on a television or radio in your home to muffle the effects of nearby fireworks. Cynthia Hubert, sacbee, "Free pet microchips available in Sacramento County before Fourth of July," 19 June 2018 The Dodgers are a full-fledged media company, with their own television and radio stations and enthusiastic participation on social media outlets. Bill Shaikin,, "Dodgers' surprise ace makes All-Star case in win over Giants," 16 June 2018 The league received more than $20 million in revenue from its television and radio rights shared over a variety of networks, including ESPN and CBS Sports. Matt Murschel,, "AAC revenue report illustrates league's need for more lucrative television contract in next cycle," 11 June 2018

Recent Examples on the Web: Verb

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 And according to a $96,000 Southwest Research Institute study commissioned by the city, Motorola radios function better under firefighting conditions. Josh Baugh, San Antonio Express-News, "Council members lobbied ahead of radio vote," 13 Feb. 2018 Police on the scene Wednesday night in Chicago radioed that thousands of people sought shelter under a bridge on Lake Shore Drive. Alicia Fabbre, Elgin Courier-News, "'I felt the shock': St. Charles fire captain, Plainfield paramedic credited with saving lives of 2 lightning strike victims," 6 July 2018 In 1965, Cohen was caught radioing information to Israel. Aron Heller, Fox News, "Israel's Mossad spy agency shrouded in mystery and mystique," 1 May 2018 At a cornfield near Granjeno, Texas, Medina abruptly parked his car and ran into the muddy rows of corn stalks after the suspect, as a Marine helicopter circled overhead and radioed the suspect's location. Rick Jervis, USA TODAY, "'It's a game of hide-and-seek': A look at how Border Patrol apprehends illegal immigrants," 21 June 2018 In Thursday's exercise, the first four officers had to find one another, radio their situation and work their way through the building, stalking after the gun blasts that trainers fired from airguns. Joe Robertson, kansascity, "Making terror real: Police active-shooter training is meant to overwhelm | The Kansas City Star," 15 Mar. 2018 The officer was able to radio in to report what had happened to him, as well as information about the pickup that hit him. Teri Figueroa,, "San Diego motorcycle officer hit, goes down embankment," 4 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.

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


radio entry 2 or radio-


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 \
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

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).


the setting in which something occurs

Get Word of the Day daily email!

Test Your Vocabulary

Musical Words Quiz

  • gramophone
  • Which word describes a musical performance marked by the absence of instrumental accompaniment?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Word Winder's CrossWinder

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!