Close front rounded vowel

The close front rounded vowel, or high front rounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is $\langle\rangle$, and the equivalent X-SAMPA symbol is y. Across many languages, it is most commonly represented orthographically as $\langleü\rangle$ (in German and Turkish) or $\langley\rangle$, but also as $\langleu\rangle$ (in French and a few other Romance languages); $\langleiu\rangle$/$\langleyu\rangle$ (in the romanization of various Asian languages); $\langleű\rangle$ (in Hungarian for the long duration version; the short version is the $\langleü\rangle$ found in other European alphabets); or $\langleуь\rangle$ (in Cyrillic-based writing systems such as that for Chechen)

Short and long  occurred in pre-Modern Greek. In the Attic and Ionic dialects of Ancient Greek, front developed by fronting from back  around the 6th to 7th century BC. A little later, the diphthong  when not before another vowel monophthongized and merged with long. In Koine Greek, the diphthong changed to, likely through the intermediate stages  and. Through vowel shortening in Koine Greek, long merged with short. Later, unrounded to, yielding the pronunciation of Modern Greek. For more information, see the articles on Ancient Greek and Koine Greek phonology.