transponder

noun

tran·​spon·​der tran(t)-ˈspän-dər 

: 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

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

Chilima’s United Transformation Movement political party − not the president's party − said there was no transponder on the plane and criticized the the government response as slow. —John Bacon, USA TODAY, 11 June 2024

The new rates will be in effect until June 30 of next year and range between $2.61 and $15.61, depending on the vehicle size and whether the driver has a prepaid account and transponder or not. —Ana Rocío Álvarez Bríñez, The Courier-Journal, 18 June 2024

The ships, which included one missile frigate and two support vessels, could be tracked almost on real time thanks to signals sent by their transponders, which these companies track as part of their services. —Antonio Maria Delgado, Miami Herald, 12 June 2024

The system, which can pick up signals from E-ZPass transponders and photograph license plates, would have assessed tolls and tracked individual vehicles in order to determine when a levy was not necessary. —Evan Simko-Bednarski, New York Daily News, 5 June 2024

Word History

Etymology

transmitter + responder

First Known Use

circa 1944, in the meaning defined above