U+A651 Cyrillic Small Letter Yeru with Back Yer

The Wikipedia has the following information about this codepoint:

Yeru or Eru (Ы ы; italics: Ы ы), usually called Y [ɨ] in modern Russian or Yery or Ery historically and in modern Church Slavonic, is a letter in the Cyrillic script. It represents the close central unrounded vowel /ɨ/ (more rear or upper than i) after non-palatalised (hard) consonants in the Belarusian and Russian alphabets.

The letter is usually romanised ⟨y⟩, such that the family name Крылов is usually written Krylov in English and most other West European languages. That spelling matches the Latin alphabet used for the Slavic language Polish, whose letter ⟨y⟩ represents the same sound. Similarly, ⟨ы⟩ is used for ⟨y⟩ in the cyrillisation of Polish, such that the name Maryla appears as Марыля in Russian. Note, however, that the letter ⟨y⟩ also appears in romanisation of other Russian letters both in isolation (such as ⟨й⟩, y) and as part of digraphs (such as ⟨я⟩, ya).

In Rusyn, ⟨ы⟩ represents the close-mid back unrounded vowel /ɤ/. In most Turkic languages that use Cyrillic, such as Kazakh and Kyrgyz, ⟨ы⟩ is used to represent the close back unrounded vowel /ɯ/ instead.