A single or unmarried person. rare.

One who is alone or unaccompanied, as an only child or unmarried person. Also spec. an undercover agent who operates alone.

elliptical in general application. An unmarried or unaccompanied man or woman; a person living alone. Frequently plural.

North American. Esp. in estate agents' jargon: an unmarried person who shares a residence with another of roughly the same age who is not usually a…