What is "obstruent"

Obstruent \Ob"stru*ent\, a. [L. obstruens, p. pr. of obstruere. See Obstruct.] Causing obstruction; blocking up; hindering; as, an obstruent medicine.
--Johnson.

Obstruent \Ob"stru*ent\, n. Anything that obstructs or closes a passage; esp., that which obstructs natural passages in the body; as, a medicine which acts as an obstruent.

a. Causing obstruction; blocking up; hindering. n. (context phonetics English) a consonant sound formed by obstructing the airway, causing turbulence; the generic term of plosive, fricative and affricate

An obstruent is a speech sound such as , , or that is formed by obstructing airflow. Obstruents contrast with sonorants, which have no such obstruction and therefore resonate. All obstruents are consonants, whereas sonorants include vowels and consonants.

Obstruents are subdivided into plosives (oral stops), such as , with complete occlusion of the vocal tract, often followed by a release burst; fricatives, such as , with limited closure, not stopping airflow but making it turbulent; and affricates, which begin with complete occlusion but then release into a fricative-like release, such as . Obstruents are prototypically voiceless, though voiced obstruents are common. This contrasts with sonorants, which are prototypically voiced and only rarely voiceless.