What is the meaning of Responder?

One who responds.

A person who responds to an emergency situation or other summons.

to respond

respond

to answer; to reply

to answer

to answer; to reply (to give a written or spoken response)

to answer; to reply (to give a written or spoken response)

to answer; to reply (to give a written or spoken response)

to answer; to reply (to give a written or spoken response)

to retort frequently

to correspond to (to be equivalent to)

to counterattack

to be responsible (for something)

to be a defendant

to answer, to reply

to talk back, to answer back

to respond, to react

to answer for, to be responsible for, vouch for

to react, to respond

Source: wiktionary.org