What does "transponder" mean?

A radar or radio transceiver that transmits some signal in response to receiving a predetermined signal.

What is a synonym for "transponder"?

Common synonyms include: radar beacon, radio control, relay, responder, rfid tag, satellite relay.

Pronounced //tɹænˈspɒn.də//.

/tɹænˈspɒn.də/ noun

noun ·Rare ·Advanced level

Noun

1
A radar or radio transceiver that transmits some signal in response to receiving a predetermined signal.
"36 MHz transponder providing a pool of 794 reallocatable frequencies."
2
electrical device designed to receive a specific signal and automatically transmit a specific reply wordnet

"36 MHz transponder providing a pool of 794 reallocatable frequencies."

Blend of transmitter + responder.