What is "fricative consonant"

n. a continuant consonant produced by breath moving against a narrowing of the vocal tract [syn: fricative, spirant]

Fricatives are consonants produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of ; the back of the tongue against the soft palate, in the case of German (the final consonant of Bach); or the side of the tongue against the molars, in the case of Welsh (appearing twice in the name Llanelli). This turbulent airflow is called frication. A particular subset of fricatives are the sibilants. When forming a sibilant, one still is forcing air through a narrow channel, but in addition, the tongue is curled lengthwise to direct the air over the edge of the teeth. English , , , and are examples of sibilants.

The usage of two other terms is less standardized: "Spirant" can be a synonym of "fricative", or (as in e.g. Uralic linguistics) refer to non-sibilant fricatives only. "Strident" could mean just "sibilant", but some authors include also labiodental, lateral or uvular fricatives in the class.