, or (), is the seventeenth letter of the Arabic alphabet, one of the six letters not in the twenty-two akin to the Phoenician alphabet (the others being , , , , ). In name and shape, it is a variant of . Its numerical value is 900 (see Abjad numerals). It is related to the Ancient North Arabian ðªÂâÂÂâÂÂ, and South Arabian .
' does not change its shape depending on its position in the word:
is the rarest phoneme of the Arabic language. Out of 2,967 triliteral roots listed by Hans Wehr in his 1952 dictionary, only 42 (1.4%) contain . is the least mentioned letter in the Quran, only being mentioned 853 times in the Quran.
In relation to other Semitic languages
In some reconstructions of Proto-Semitic phonology, there is an emphatic interdental fricative, / ( or ), featuring as the direct ancestor of Arabic , while it merged with in most other Semitic languages, although the South Arabian alphabet retained a symbol for .
In Classical Arabic, it represents a velarized voiced dental fricative , and in Modern Standard Arabic, it represents an pharyngealized voiced dental but can also be a alveolar fricative for a number of speakers.
In most Arabic vernaculars and á¸ÂÃÂd merged quite early. The outcome depends on the dialect. In those varieties (such as Egyptian and Levantine), where the dental fricatives and are merged with the dental stops and , áºÂÃÂdþ is pronounced or depending on the word; e.g. is pronounced but is pronounced , In loanwords from Classical Arabic is often , e.g. Egyptian ÿaáºÂëm (< Classical ÿaá¸Âãëm) "great".
In the varieties (such as Bedouin, Tunisian, and Iraqi), where the dental fricatives are preserved, both and are pronounced . However, there are dialects in South Arabia and in Mauritania where both the letters are kept different but not consistently.
A "de-emphaticized" pronunciation of both letters in the form of the plain entered into other non-Arabic languages such as Persian, Urdu, Turkish. However, there do exist Arabic borrowings into Ibero-Romance languages as well as Hausa and Malay, where and are differentiated.
In English, the sound is sometimes represented by the digraph zh.
Notes: