Labial /(?)/

La·bi·al

Labial

a.
  1. Of or pertaining to the lips or labia; as, labial veins.
  2. Furnished with lips; as, a labial organ pipe. (Mus.)
  3. Articulated, as a consonant, mainly by the lips, as b, p, m, w. (Phonetics)
  4. Of or pertaining to the labium; as, the labial palpi of insects. See Labium. (Zool.)

Labial

n.
  1. A letter or character representing an articulation or sound formed or uttered chiefly with the lips, as b, p, w. (Phonetics)
  2. An organ pipe that is furnished with lips; a flue pipe. (Mus.)
  3. One of the scales which border the mouth of a fish or reptile. (Zool.)