tran·​spon·​der | \ tran(t)-ˈspän-dər How to pronounce transponder (audio) \

Definition of transponder

: a radio or radar set that upon receiving a designated signal emits a radio signal of its own and that is used especially for the detection, identification, and location of objects and in satellites for relaying communications signals

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Did You Know?

This word was coined during World War II by simply joining pieces of the words transmitter and responder. Transponders are basic to modern aviation and communications satellites, and they're finding new uses in fields such as medicine as well. But they're now also part of everyday life. The "E-ZPass" that lets you drive right through turnpike tollbooths is a transponder, and the car you're driving may not even start unless it recognizes the signal from your personal key's transponder. In a big crowded foot race, you may carry a tiny transponder on your shoe that records when you cross both the starting line and the finish line.

Examples of transponder in a Sentence

Recent Examples on the Web The turnpike allows for electronic payments now using an E-Z Pass transponder, but motorists must slow down, access the appropriate lane at the toll plaza, and then emerge once the gate automatically lifts. Peter Krouse, cleveland, "Ohio Turnpike not planning for all-electronic tolling because not enough use E-Z Pass," 26 June 2020 Chalet staff who saw the crash happen activated an emergency transponder, and park personnel were notified of the crash around 3:20 p.m., the park service said. Anchorage Daily News, "None injured after helicopter crashes at Ruth Glacier in Denali National Park," 22 Feb. 2020 Of course, privy to the double-crossing nature of this particular outfit, Mando left behind the New Republic transponder, and a fleet of X-Wings show up to finish the job. Darren Orf, Popular Mechanics, "The Mandalorian: An Old-Fashioned Prison Break...In Space," 13 Dec. 2019 These transponders would transmit and receive the flight plans of other aircraft in the vicinity automatically so that pilots, or in the case of autonomous aircraft their flight computers, can see and avoid one another. The Economist, "Flying taxis are taking off to whisk people around cities," 14 Sep. 2019 Travel by air and sea transponders would be down; Instagram wouldn't work on some phones; and there would be no Sirius XM radio. Deanna Paul, Anchorage Daily News, "Space: The final legal frontier," 1 Sep. 2019 Travel by air and sea transponders would be down; Instagram wouldn’t work on some phones; and there would be no Sirius XM radio. Deanna Paul, Washington Post, "Space: The final legal frontier," 31 Aug. 2019 Positive train control is technology that involves installing software and transponders to communicate about how fast trains should be going on certain areas of track. USA TODAY, "Return of Alienstock, Mardi Gras hate crime, much ado about a hat: News from around our 50 states," 19 Feb. 2020 Now, more than 100,000 commercial and general aviation aircraft have the transponders, according to the Federal Aviation Administration, including nearly all commercial aircraft and an estimated 60% of general aviation aircraft that need it. Jo Craven Mcginty, WSJ, "Air-Traffic Control Is in the Midst of a Major Change," 24 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'transponder.' 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 transponder

circa 1944, in the meaning defined above

History and Etymology for transponder

transmitter + responder

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Time Traveler for transponder

Time Traveler

The first known use of transponder was circa 1944

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Statistics for transponder

Last Updated

7 Jul 2020

Cite this Entry

“Transponder.” Dictionary, Merriam-Webster, Accessed 7 Jul. 2020.

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More Definitions for transponder


How to pronounce transponder (audio)

English Language Learners Definition of transponder

technical : a device that receives a radio signal and sends out a signal in response and that is used especially to show the location of something (such as an airplane)

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More from Merriam-Webster on transponder

Rhyming Dictionary: Words that rhyme with transponder

Nglish: Translation of transponder for Spanish Speakers Encyclopedia article about transponder

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