Elongated labia (also known as Sinus pudoris and albeit nonmedically, as khoikhoi apron or hottentot apron) is an apparently genetic feature of certain Khoisan groups, whose females develop relatively elongated labia minora, hanging up to four inches outside their vulva when they are in an upright position. The "apron" moniker was apparently gained from the tendency of early European descriptions to misidentify the pair of labia as a single, wide organ, which they called, in French, a tablier, or "apron". "Hottentot" is an acquired name for the Khoisan peoples, now seen as derogatory.
This trait was first noted as far back as the 17th century, but became extensively documented in the last part of the 18th and the 19th century.
Labia may also be shaped by intentional labia stretching, usually done by an aunt on girls beginning at the age of four or five, a practice that has been previously characterized as a form of female genital mutilation, and now, modification. Alternatively, labiaplasty may be used to reduce the appearance of elongated labia.