What is the meaning of Й?

A letter of the Cyrillic script, called short i.

The twenty-fourth letter of the Abaza alphabet, written in the Cyrillic script.

The twentieth letter of the Adyghe alphabet, written in the Cyrillic script.

The fifteenth letter of the Aghul alphabet, written in the Cyrillic script.

The fifteenth letter of the Alutor alphabet, written in the Cyrillic script.

The twenty-seventh letter of the Archi alphabet, written in the Cyrillic script.

The eleventh letter of the Buryat alphabet, written in the Cyrillic script.

The eleventh letter of the Chukchi alphabet, written in the Cyrillic script.

The fourteenth letter of the Dargwa alphabet, written in the Cyrillic script.

The thirteenth letter of the Dungan alphabet, written in the Cyrillic script.

The eleventh letter of the Eastern Mari alphabet, written in the Cyrillic script.

The eleventh letter of the Even alphabet, written in the Cyrillic script.

The eleventh letter of the Evenki alphabet, written in the Cyrillic script.

The thirteenth letter of the Ingush alphabet, written in the Cyrillic script.

The twelfth letter of the Itelmen alphabet, written in the Cyrillic script.

The eighteenth letter of the Kabardian alphabet, written in the Cyrillic script.

The twelfth letter of the Khakas alphabet, written in the Cyrillic script.

The thirteenth letter of the Kumyk alphabet, written in the Cyrillic script.

The eleventh letter of the Kyrgyz alphabet, called ий (iy), and written in the Cyrillic script.

The thirteenth letter of the Lezgi alphabet, written in the Cyrillic script.

The fourteenth letter of the Nivkh alphabet, written in the Cyrillic script.

The fifteenth letter of the Northern Mansi alphabet, written in the Cyrillic script.

The twelfth letter of the Southern Altai alphabet, written in the Cyrillic script.

The fourteenth letter of the Tabasaran alphabet, written in the Cyrillic script.

The eleventh letter of the Tundra Nenets alphabet, written in the Cyrillic script.

The twelfth letter of the Western Mari alphabet, written in the Cyrillic script.

The thirteenth letter of the Yakut alphabet, called ый (ıy), and written in the Cyrillic script.

The fourteenth letter of the Avar alphabet, written in the Cyrillic script.

The thirteenth letter of the Bashkir alphabet, written in the Cyrillic script.

The eleventh letter of the Belarusian alphabet, written in the Cyrillic script.

and (variant of і (i), sometimes used after vowels in the Taraškievica standard and in poetry)

The tenth letter of the Bulgarian alphabet, called и кратко (i kratko), and written in the Cyrillic script.

The thirteenth letter of the Chechen alphabet, written in the Cyrillic script.

The thirteenth letter of the Chuvash alphabet, written in the Cyrillic script.

The twelfth letter of the Crimean Tatar alphabet, written in the Cyrillic script.

The fourteenth letter of the Kalmyk alphabet, written in the Cyrillic script.

The thirteenth letter of the Kazakh alphabet, written in the Cyrillic script.

The eleventh letter of the Mongolian alphabet, called хагас и (xagas i) or хагас й (xagas j), and written in the Cyrillic script.

The fifteenth letter of the Ossetian alphabet, written in the Cyrillic script.

The eleventh letter of the Moldovan alphabet, written in the Cyrillic script.

The eleventh letter of the Russian alphabet, called и краткое (i kratkoje) or ий (ij), and written in the Cyrillic script.

The thirteenth letter of the Tajik alphabet, written in the Cyrillic script.

The thirteenth letter of the Tatar alphabet, written in the Cyrillic script.

The eleventh letter of the Tuvan alphabet, written in the Cyrillic script.

The fourteenth letter of the Udmurt alphabet, written in the Cyrillic script.

The fourteenth letter of the Ukrainian alphabet, called йот (jot) or й (j), and written in the Cyrillic script.

and

The eleventh letter of the Uzbek alphabet, written in the Cyrillic script.

Source: wiktionary.org