responder

[ ri-spon-der ]
/ rɪˈspɒn dər /

noun

a person or thing that responds.
Electronics. the part of a transponder that transmits the reply.

Origin of responder

First recorded in 1875–80; respond + -er1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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