What does bilabial mean?
Bilabial is a technical term from phonetics describing speech sounds that are articulated with both lips working together. The most familiar examples in English are the consonants /p/, /b/, and /m/, where the lips close fully or nearly so to shape the airflow — think of the opening sounds of 'pat', 'bat', and 'mat'. Used chiefly as an adjective ('a bilabial stop'), it also serves as a noun referring to any such sound. The term appears mainly in linguistics, language teaching, speech therapy, and singing instruction, rather than everyday speech. Its precision matters because it distinguishes these two-lip sounds from related categories such as labiodental consonants like /f/ and /v/, which involve the teeth. Beyond its technical value, the word offers a neat example of how descriptive terminology encodes anatomy: 'bilabial' literally means 'two-lipped'. For anyone studying how languages are built from a small set of articulatory gestures, bilabial is one of the foundational labels for classifying consonants.
(Of a speech sound) Produced with both lips, as /p/, /b/, and /m/ in English.
"The bilabial nasal /m/ occurs in virtually every known language."
A speech sound produced with both lips, such as /p/, /b/, or /m/.
"English has three common bilabials: /p/, /b/, and /m/."
Usually encountered in the plural form 'bilabials' in linguistic writing.
Standard plural, used when discussing bilabial sounds as a class across languages.
"Many languages have fewer bilabials than English does."
Every time you say 'mum' or 'pop', your lips do all the work — those are bilabial sounds, among the first consonants human babies learn to make.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bilabial
The word bilabial derives from the prefix 'bi-', meaning 'two', combined with 'labial', which traces back to the Latin 'labium', meaning 'lip'. It entered scientific usage in the nineteenth century as linguists developed systematic classifications of speech sounds based on their place of articulation. It shares this Latin root with related terms such as 'labial' and 'labiodental', as well as anatomical uses of 'labium'.
Related word forms
How bilabial is actually used
A technical term used almost exclusively in linguistics, phonetics, speech pathology, and language teaching; it is rare in general conversation. The noun is most often used in the plural ('the bilabials of English').
Easily confused with bilabial
'Labial' covers any lip-involved sound including labiodental ones like /f/ and /v/, while 'bilabial' specifically requires both lips, as in /p/, /b/, and /m/.
Labiodental sounds are made with the lower lip against the upper teeth (e.g., /f/, /v/), whereas bilabial sounds use both lips together.