transponder

or tran·spon·dor

[ tran-spon-der ]

noun

1. a radio, radar, or sonar transceiver that automatically transmits a signal upon reception of a designated incoming signal.

transponder

/ trænˈspɒndə /

noun

1. a type of radio or radar transmitter-receiver that transmits signals automatically when it receives predetermined signals
2. the receiver and transmitter in a communications or broadcast satellite, relaying received signals back to earth

transponder

/ trăn-spŏn′dər /

1. A radio or radar transmitter and receiver that responds to an incoming signal either by broadcasting its own predetermined signal (as in aircraft identification systems) or by relaying the incoming signal at a different frequency (as in satellite communications).

Word History and Origins

Origin of transponder¹

First recorded in 1940–45; trans(mitter) + (res)ponder

Word History and Origins

Origin of transponder¹

C20: from transmitter + responder

Example Sentences

Nothing from the transponder, a device that sends an airplane’s airline identification, flight number, speed and altitude to the radar screens.

From Washington Post

Her startup, Astrome, is building satellites that carry transponders with 11 times the capacity of those now commonly used, which could revolutionize internet access in remote parts of the world.

From Ozy

For example, people traveling on Maryland toll roads without an E-ZPass transponder are billed by mail.

From Washington Post

Without a cash option, drivers without an E-ZPass transponder are billed the toll via the mail.

From Washington Post

Payments are deducted from accounts when vehicles equipped with transponders use the system.

From Washington Post

The tripwire for an unfolding plot to take control of the flight would be the transponder, operated by a switch beside the pilots.

From The Daily Beast

However, to use the phrase “switched off” in relation to the transponder and the ACARS was in itself prejudicial.

From The Daily Beast

With so much else crumbling, the transponder lies at the heart of this great mystery.

From The Daily Beast

Government officials now admit the data system and transponder quit communicating after the pilots said things were OK.

From The Daily Beast

The transponder is really the tripwire for whatever began to unfold on that jet.

From The Daily Beast