negative response

1. In a communications system, a response that indicates that a message was not successfully received. 2. In a communications system, a response that indicates that a message or a request arrived, was unsuccessfully received, and therefore has not been processed. 3. In data communications, a reply that indicates (a) data were (i) not received correctly or (ii) incorrect data were received and (b) a received command was incorrect or unacceptable. Synonymabnormal response. See alsocommand, communications system, data, data communications, indicator, message, positive response, process, receive, reply, response, request.