labium

labium {laybiəm}
noun (pl. labia /laybiə/)

1. (labia) anatomy the inner and outer folds of the vulva.
2. a fused mouthpart forming the floor of the mouth of an insect.

(OED)

In most Western cultures, as the most visible portion of the female genitals, the labia are frequently considered to be private or intimate parts, the exposure of which is governed by fairly strict socio-cultural mores.

Some women, particularly those involved in pornography or exotic dancing, seek labiaplasty to alter the appearance of their labia.

(wiki)