transponder

Nothing from the transponder, a device that sends an airplane’s airline identification, flight number, speed and altitude to the radar screens.
Sept. 11, 2001: An ordinary work day, then surreal scenes of dread and death|David Maraniss|September 10, 2021|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.
Escape Velocity: The Road To Space|Leslie dela Vega|July 11, 2021|Ozy
For example, people traveling on Maryland toll roads without an E-ZPass transponder are billed by mail.
Out-of-state drivers owe more than $167 million to Maryland. The state wants to recoup the unpaid tolls.|Luz Lazo|May 7, 2021|Washington Post
Without a cash option, drivers without an E-ZPass transponder are billed the toll via the mail.
Out-of-state drivers owe more than $167 million to Maryland. The state wants to recoup the unpaid tolls.|Luz Lazo|May 7, 2021|Washington Post

Payments are deducted from accounts when vehicles equipped with transponders use the system.
Virginia pauses deactivation of idle E-ZPass accounts amid pandemic|Justin Wm. Moyer|February 3, 2021|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.
Who Gagged the Search for MH370?|Clive Irving|June 22, 2014|DAILY BEAST
However, to use the phrase “switched off” in relation to the transponder and the ACARS was in itself prejudicial.
Who Gagged the Search for MH370?|Clive Irving|June 22, 2014|DAILY BEAST
With so much else crumbling, the transponder lies at the heart of this great mystery.
Malaysia’s Sinister Timeline for Flight 370 Unravels|Clive Irving|March 18, 2014|DAILY BEAST
Government officials now admit the data system and transponder quit communicating after the pilots said things were OK.
Malaysia’s Sinister Timeline for Flight 370 Unravels|Clive Irving|March 18, 2014|DAILY BEAST
The transponder is really the tripwire for whatever began to unfold on that jet.
The Tripwire on Flight 370|Clive Irving|March 17, 2014|DAILY BEAST

British Dictionary definitions for transponder

transponder

transpondor

/ (trænˈspɒndə) /

noun

a type of radio or radar transmitter-receiver that transmits signals automatically when it receives predetermined signals

the receiver and transmitter in a communications or broadcast satellite, relaying received signals back to earth

Word Origin for transponder

C20: from transmitter + responder

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for transponder

transponder

[ trăn-spŏn′dər ]

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).