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
Recent Examples of transponder from the Web
Motorists with E-ZPass transponders now will pay $10.52 to travel the Toll Road's full length, up from $4.65.
By leveraging and installing wireless transponders called Roadside Units or similar smart embedded sensors, cars can feed safety information into our highways and rural roads.
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.
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.
Origin and Etymology of transponder
transmitter + responder
First Known Use: circa 1944See Words from the same year
TRANSPONDER Defined for English Language Learners
Definition of transponder for English Language Learners
: 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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