Definition

1. Adjective:

   • Relating to a speech sound: Describes a speech sound, typically a consonant, that is produced by bringing both lips together or into close proximity.

2. Noun:

   • A type of consonant: A consonant sound that is articulated using both lips.

Examples of Usage

• Adjective:

  • The sounds /p/ and /b/ are bilabial consonants.
  • In phonetics, a bilabial articulation involves the action of both lips.

• Noun:

  • The English phoneme /m/ is a voiced bilabial.
  • The word "we" begins with the bilabial /w/.

Advanced Usage

• Bilabial trill: A rare consonant sound, represented by the IPA symbol [ʙ], produced by vibrating the lips together.
• Bilabial click: A type of click consonant found in some African languages, produced with an ingressive airflow and lip closure.

Variants and Related Words

• Labial (adj/n): A broader term for sounds made with the lips, which includes both bilabial (two lips) and labiodental (lip and teeth) articulations.

Synonyms

• Labial (in its broader sense, when context clarifies the use of both lips).

Related Terms (Linguistics/Phonetics)

• Place of articulation: The point in the vocal tract where a consonant sound is produced. "Bilabial" is a primary place of articulation.
• Manner of articulation: How the airflow is obstructed to produce a sound (e.g., plosive, nasal, fricative). Bilabial sounds can have different manners.
• Voicing: Whether the vocal cords vibrate during the sound's production. For example, /b/ is a voiced bilabial plosive, while /p/ is its voiceless counterpart.

Adjective

1. of or relating to or being a speech sound that is articulated using both lips
   • bilabial fricatives

Noun

1. a consonant that is articulated using both lips; /p/ or /b/ or /w/