Labialization is a phonetic term that refers to the articulation of sounds using the lips. Although labialization is usually associated with vowels and consonants that involve the lips, such as [w] or [b], there are several synonyms that can be used to describe this type of sound production. These include lip rounding, lip protrusion, and bilabial sounds. Lip rounding refers to the circular movement of the lips that results in a rounded or pursed appearance, while lip protrusion indicates the extreme forward movement of the lips. Bilabial sounds, on the other hand, involve the use of both lips to articulate a sound. Understanding these synonyms can help linguists and language learners better understand how phonemes are produced in different languages.