Definition & Meaning of "roast beef curtain"in English

What is the origin of the term "roast beef curtain" and how is it used?

"Roast beef curtain" is a slang term for the labia minora that appeared in late 20th-century English, mainly in informal, sexual, or shock-humor contexts. The term uses "roast beef" as a crude visual metaphor for the color or texture of the inner labia, and "curtain" to describe the way the folds hang, creating a graphic image of the anatomy. It is used in joking, sexual, or derogatory speech, often to mock or objectify women's bodies. The term is vulgar, sexual, and never neutral, and inappropriate in polite or formal settings.