labiodental

Labiodental refers to a place of articulation for consonants produced with the lower lip contacting the upper teeth. In this configuration the lower lip either touches or comes close to the upper incisors to create a constriction through friction or obstruction. This articulatory location is distinct from dental (tongue against teeth) and bilabial (both lips).

The most common labiodental consonants are the voiceless fricative [f] and the voiced fricative [v]. Some languages also feature a labiodental nasal [ɱ], produced with the lower lip and upper teeth, and a voiced labiodental approximant [ʋ], which in some languages is analyzed as a fricative rather than an approximant. The exact inventory of labiodental sounds varies across languages, and not all languages contrast all possible labiodental phonemes.

In language practice, labiodental sounds typically function as sibilant or fricative elements, often behaving like other fricatives in processes such as voicing contrast, assimilation, and coarticulation with surrounding vowels and consonants. English, French, and many other languages use [f] and [v], with the presence and phonemic status of other labiodental sounds differing by language. The term labiodental is used across phonetics and phonology as a standard descriptor of sounds produced by the contact between the lower lip and upper teeth.