What is the meaning of а?

A letter of the Cyrillic script, called a.

A letter of the Old Cyrillic script, called az or azu.

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

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

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

that, Calling article (o)

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

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

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

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

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

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

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

and, but (used to connect two phrases when there is a contrast between them)

but, but instead (used in clauses preceded by negated clauses)

and, but (introduces supplementary questions)

so, huh (particle placed at the end of questions)

oh

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

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

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

The first letter of the Hunzib alphabet, written in the Cyrillic script.

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

and

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

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

six

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

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

The first letter of the Kyrgyz alphabet, called а (a), and written in the Cyrillic script.

The name of the Cyrillic script letter А / а.

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

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

armspan

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

but, and

A letter of the Old Novgorodian alphabet, written in the Old Cyrillic script.

but, and

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

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

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

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

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

The first letter of the Yakut alphabet, called а (a), and written in the Cyrillic script.

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

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

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

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

but, and, and yet (deviates from the preceding idea in some manner; introduces a new or different meaning, as opposed to но (no), which usually indicates contrarity)

interrogative particle: introduces a question

ah!, oh!, oh well

The first letter of the Bulgarian alphabet, called а (a), and written in the Cyrillic script.

used in orders for emphasis: let’s, just

just, about to, on the point of, almost

used to express surprise or wonder: ah, oh, ha, why

used to express pleasure, relief: ah

used when you are not certain about something and you would like confirmation: eh, well, right, or translated with a tag question

used to indicate that one did not hear what was said: eh, huh

used to express understanding, recognition, or realization: oh

used to express displeasure, objection

used to express criticism or disapproval: now

used to describe how two facts are different: whereas, while

used to introduce an idea that is different or opposite to the idea that is desired, expected or that you have stated previously: but, yet, rather

used to start a new sentence or clause that continues or adds to a previous sentence or clause: and

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

and

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

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

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

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

ah (expression of surprise)

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

and, whereas

oh

huh?

what about

The first letter of the Mongolian alphabet, called а (a), and written in the Cyrillic script.

The name of the Cyrillic script letter А / а.

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

and

but

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

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

The first letter of the Russian alphabet, called а (a), and written in the Cyrillic script.

The name of the Cyrillic script letter А / а.

The name of the Latin-script letter A/a.

but, and (deviates from the preceding idea in some manner; introduces a new or different meaning, as opposed to но (no), which usually indicates contrarity)

oh! (expressing surprise or realization)

colloquial particle used to seek confirmation: eh

he, she or it (used to point to a particular person)

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

but, and (compare а̏ли)

while (on the contrary), whereas

without (usually after negative verbs)

(а и̏па̄к) and yet

(а ка̏моли) not to mention, let alone

(а + и + да) even if

(а + и) and so, and also, and too

oh, ah

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

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

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

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

The first letter of the Ukrainian alphabet, called а (a), and written in the Cyrillic script.

and, and yet, but

interrogative particle: introduces a question

ah!, oh!, oh well

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

Source: wiktionary.org