Uk (Cyrillic)
Uk (Ѹ ѹ; italics: Ѹ ѹ or Оу оу) is a letter of the early Cyrillic alphabet, although commonly considered and used as a single letter. It is an accent nasal vowel from Slavonic language. To save space, it was often written as a vertical ligature (Ꙋ ꙋ), called "monograph Uk".  In modern times, Ѹ is extremely rare nowadays and is still used in Church Slavonic.