What is the meaning of б?

A letter of the Cyrillic script, called be.

A letter of the Old Cyrillic script, called buky or buki.

The second letter of the Abaza alphabet, written in the Cyrillic script.

The second letter of the Abkhaz alphabet, written in the Cyrillic script.

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

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

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

The sixth letter of the Archi alphabet, written in the Cyrillic script.

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

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

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

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

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

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

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

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

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

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

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

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

The second letter of the Kyrgyz alphabet, called бе (be), and written in the Cyrillic script.

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

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

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

The third letter of the Orok alphabet, written in the Cyrillic script.

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

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

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

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

The second letter of the Yakut alphabet, called бэ (be), and written in the Cyrillic script.

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

The second letter of the Azerbaijani alphabet, written in the Cyrillic script.

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

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

The second letter of the Bulgarian alphabet, called бъ (b), and written in the Cyrillic script.

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

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

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

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

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

The second letter of the Macedonian alphabet, written in the Cyrillic script.

The second letter of the Mongolian alphabet, called бэ (be), and written in the Cyrillic script.

A letter of the Old Church Slavonic alphabet, called боукꙑ (buky), and written in the Old Cyrillic script.

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

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

The second letter of the Russian alphabet, called бэ (bɛ), and written in the Cyrillic script.

Alternative form of бы (by)

The second letter of the Serbo-Croatian alphabet, written in the Cyrillic script.

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

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

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

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

The second letter of the Ukrainian alphabet, called бе (be), and written in the Cyrillic script.

would, expresses a conditional statement (following a vowel)

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

Source: wiktionary.org