bi·labial I. \(ˈ)bī+\adjective Etymology: International Scientific Vocabulary bi- (I) + labial 1.of a consonant: produced with both lips < \p\ and \b\ and \m\ are bilabial consonants > — compare labial 2. a.: of, relating to, or between the lips b.anthropology: between the highest point on the upper lip and the lowest point on the lower lip II. noun (-s) : a bilabial consonant