1. Adj (Phonetics & Phonology) of, relating to, or denoting a speech sound articulated using both lips: (p) is a Bilabial stop, (w) a Bilabial semivowel.

2. Adj (Phonetics & Phonology) of, relating to, or denoting a speech sound articulated using both lips: (p) is a Bilabial stop, (w) a Bilabial semivowel.