Ayin (also ayn or ain; transliterated ⟨ʿ⟩) is the sixteenth letter of the Semitic scripts, including Phoenician ʿayin 𐤏, Hebrew ʿayin ע, Aramaic ʿē 𐡏, Syriac ʿē ܥ, and Arabic ʿayn ع (where it is sixteenth in abjadi order only).
In the revived Modern Hebrew it is reduced to a glottal stop or is omitted entirely, in part due to Ashkenazi European influence and their difficulty in pronouncing the consonant.
[1] The Phoenician letter gave rise to the Greek Ο, Latin O, and Cyrillic О, all representing vowels.
Due to its position as the innermost letter to emerge from the throat, al-Khalil ibn Ahmad al-Farahidi, who wrote the first Arabic dictionary, actually started writing his Kitab al-'Ayn ('The Book of ʿAyn') with ʿayn as the first letter instead of the eighteenth; he viewed its origins deep down in the throat as a sign that it was the first sound, the essential sound, the voice and a representation of the self.
When pointing was developed, the sound /ʁ/ was distinguished with a dot on top (غ), to give the letter ghayn.
In Maltese, which is written with the Latin alphabet, the digraph għ, called għajn, is used to write what was originally the same sound.
In Israeli Hebrew (except for Mizrahi pronunciations), it represents a glottal stop in certain cases but is usually silent (it behaves the same as aleph).
ʿayin is also one of the seven letters which receive special crowns (called tagin) when written in a sefer Torah.
The shape of the "raised semi-circle" for ayin ⟨ʿ⟩ and alef ⟨ʾ⟩ was adopted by the Encyclopedia of Islam (edited 1913–1938, 1954–2005, and from 2007), and from there by the International Journal of Middle East Studies.
A notable exception remains, ALA-LC (1991), the system used by the Library of Congress, continues to recommend modifier letter turned comma ⟨ʻ⟩ (for Hebrew) or left single quotation mark ⟨‘⟩ (for Arabic).
[7] The symbols for the corresponding phonemes in the International Phonetic Alphabet, ⟨ʕ⟩ for pharyngeal fricative (ayin) and ⟨ʔ⟩ for glottal stop (alef) were adopted in the 1928 revision.
There are a number of alternative Unicode characters in use, some of which are easily confused or even considered equivalent in practice:[8] Letters used to represent ayin: The phonemes corresponding to alef and ayin in Ancient Egyptian are by convention transliterated by more distinctive signs: Egyptian alef is rendered by two semi-circles open to the left, stacked vertically, and Egyptian ayin is rendered by a single full-width semi-circle open to the right.