noun
transponder
tran-SPON-duh
noun
1
A device that automatically sends out a signal when it receives a particular incoming signal.
"Air traffic control tracks planes using the signal from each aircraft's transponder."
"The tollbooth read the car's transponder as it passed under the sensor."
How to Use Transponder
Learner’s notesIn plain EnglishA gadget that replies automatically when it's pinged by the right signal — used in aircraft, tollbooths, and tracking systems.
Common pairings
aircraft transponder
radio transponder
Word Forms
transponders plural
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Air traffic control tracks planes using the signal from each aircraft's _____.
Etymology
A blend of "transmitter" and "responder."