la·bi·al 
(lābē-əl)
(lābē-əl)adj.
1. Of or relating to the lips or labia.
2. Linguistics Articulated mainly by closing or partly closing the lips, as the sounds (b), (m), or (w).
n.
1. Linguistics A labial consonant.
2. Music See flue1.
[Medieval Latin labiālis, from Latin labium, lip; see leb- in the Appendix of Indo-European roots.]
labi·al·ly adv.