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