What is the meaning of آ?

Alif maddah. A double-alif used to write the sequence /ʔaː/.

A form of the initial interrogative particle that indicates a yes-or-no question. As it is written together with the following word, when this word begins with ال (al-, the) they are orthographically morphed together and written with a مَدَّة (madda) diacritic instead of maintaining both.

I (nominative)

The first other alif letter of the Khowar abjad.

The first letter of the Ushojo abjad.

and

a vowel of Kashmiri.

yes, yeah

alif with madda, a form of ا, the first letter of the Pashto alphabet

alef-e madde

â-ye bâ-kolâh (آی باکلاه = Alef with hat)

present stem form of آمدن (âmadan)

A vowel of Punjabi, written in the Shahmukhi script. The variant of alif used for initial /aː/.

inflection of آݨا (āṇā):

  1. stem
  2. second-person singular familiar imperative

stem

second-person singular familiar imperative

A vowel of Urdu, the variant of alif used for initial /aː/.

Source: wiktionary.org