- a radio, radar, or sonar transceiver that automatically transmits a signal upon reception of a designated incoming signal.
Origin of transponder
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for transponder
The tripwire for an unfolding plot to take control of the flight would be the transponder, operated by a switch beside the pilots.
However, to use the phrase “switched off” in relation to the transponder and the ACARS was in itself prejudicial.
With so much else crumbling, the transponder lies at the heart of this great mystery.
Government officials now admit the data system and transponder quit communicating after the pilots said things were OK.
The moment the transponder turned off means everything to the investigation—and it happened after the pilots said things were OK.The Tripwire on Flight 370
March 17, 2014
- 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
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
Word Origin and History for transponder
1945, from trans(mit) + (res)pond + agent noun suffix -er (1).
Online Etymology Dictionary, © 2010 Douglas Harper
- 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).
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.