Douglas Harper's Etymology Dictionary
inner folds of skin around the vulva, 1781, Modern Latin, literally "lesser lips" (see labia). The singular is labium minus.
Wiktionary
n. (context anatomy English) The two inner folds of skin within the cleft of the labia majora.
WordNet
n. the two inner folds of the vulva
Wikipedia
The labia minora (the Latin for small lips, singular: labium minus "small lip"), also known as the inner labia, inner lips, vaginal lips or nymphae, are two flaps of skin on either side of the human vaginal opening in the vulva, situated between the labia majora (the Latin for big lips; also called outer labia, or outer lips). Inner lips vary widely in size, color, and shape from individual to individual.
Usage examples of "labia minora".
Surprisingly, she had not been raped, but there were some abrasions of the labia minora of the vulva that indicated rape had been attempted.