fricative (n.)

A term used in the PHONETIC classification of CONSONANT sounds on the basis of their MANNER OF ARTICULATION: also sometimes called spirant, it refers to sounds made when two organs come so close together that the air moving between them produces audible FRICTION, or FRICATION. There is no complete CLOSURE between the organs (in which case a PLOSIVE articulation would be produced): there is simply a STRICTURE, or narrowing. There are several such sounds in English, both VOICED and voiceless, as in fin [f], van [v], thin [θ], this , sin [s], zoo [z], ship , measure , hoop [h]. Other fricative sounds may be heard in English, in restricted CONTEXTS or speech STYLES, such as the PALATAL fricative [ç], and several other fricatives may be heard in other languages, e.g. a voiceless VELAR fricative [x] in Welsh or German, a voiceless PHARYNGEAL fricative  in Arabic, a voiced BILABIAL fricative [β] in Spanish. The fricative manner of articulation produces a wider range of speech sounds than any other. They are sounds with a potential for considerable DURATION (e.g. s-s-s), and, from this point of view, the opposite of fricative (i.e. a continuant sound lacking friction) is called a FRICTIONLESS CONTINUANT. The term spirantization is sometimes used for the process of deriving a fricative from some other type of articulation.