A with macron (Cyrillic)
A with macron is a letter of the Cyrillic script. In all its forms it looks exactly like the Latin letter A with macron.
A with macron is used in the Aleut, Evenki, Ingush, Mansi, Nanai, Orok, Ulch, Kildin Sami, Selkup, and Chechen languages.
A with macron also appears in the Bulgarian and Serbian languages in some dialects.
Usage
A with macron is used in the South Slavic languages mostly in Bulgarian usually used before or after another stressed vowel: глāвà, крāкà, овчāрè, ковāчè, юнāцѝ, and граждāнè.
Being a relatively recent letter, not present in any legacy 8-bit Cyrillic encoding, the letter А̄ is not represented directly by a precomposed character in Unicode either; it has to be composed as А+◌̄.