A person who listens, especially someone who pays attention to and understands what is being said. She is a great listener and always offers helpful advice.
A device or system that receives audio signals, such as a radio or audio receiver. The listener picked up the broadcast from the distant station.
Computing: a program, process, or routine that waits for and acts upon specific events, messages, or network requests. The server starts a socket listener on port 3000 to accept incoming connections.