Definitions

1. noun

A person who responds, especially to an emergency or a crisis, such as a police officer, firefighter, or emergency medical technician.

“The city’s emergency responders worked tirelessly to rescue people trapped in the floodwaters.”

2. verb

To respond or answer, especially to a question or a situation.

“She responded quickly to the news and offered her support to the family.”

3. noun

A device or system that sends a response or a signal, such as a radio responder or a computer responder.

“The satellite’s responder system allowed it to communicate with Earth.”