General English

  • noun something that you do or say as a reaction to something



  • A change in the behavior, operation, or function of a component, circuit, device, piece of equipment, system, mechanism, process, material, or the like, as a consequence of a change in its external or internal environment. For example, a change in output resulting from a change in input.
  • A quantified response (1), such as a frequency response.
  • The automatic emission of the appropriate signals when specified trigger signals are received, as seen, for instance, in a responder (1). Also called reply.
  • synonymreply

Information & Library Science

  • noun a reaction or reply to an event, action or statement


  • noun a reaction by an organ, tissue or a person to an external stimulus


  • noun an act of responding