Толковый словарь английского языка Oxford English Reference - labial

adj. & n. --adj. 1 a of the lips. b Zool. of, like, or serving as a lip, a liplike part, or a labium. 2 Dentistry designating the surface of a tooth adjacent to the lips. 3 Phonet. (of a sound) requiring partial or complete closure of the lips (e.g. p, b, f, v, m, w; and vowels in which lips are rounded, e.g. oo in m oon). --n. Phonet. a labial sound. Phrases and idioms labial pipe Mus. an organ-pipe having lips; a flue-pipe. Derivatives labialism n. labialize v.tr. (also -ise). labially adv. Etymology: med.L labialis f. L labia lips