n. (pl. labia) 1 (usu. in pl.) Anat. each of the two pairs of skin folds that enclose the vulva. 2 the lower lip in the mouth-parts of an insect or crustacean. 3 a lip, esp. the lower one of a labiate plant's corolla. labia majora the larger outer pair of labia (in sense 1). labia minora the smaller inner pair of labia (in sense 1).
[ L, = lip ]