Refers to a prostitute operating outside the official licensed system, often in historical or legal contexts. Contrasts with 公娼 (licensed prostitute).
See also: 公娼
Before the war, unlicensed prostitutes were distinguished from licensed ones.
Compound of 私 (private, unofficial) and 娼 (prostitute). The term emerged in contexts where prostitution was regulated and a distinction between licensed and unlicensed practitioners was necessary.