AA abbr. 1. Bible Acts of the Apostles 2. Alcoholics Anonymous 3. antiaircraft 4. Associate in Arts a·a or a’a (ä′ä) n. Lava having a rough surface. [Hawaiian ‘a’ā, to burn, aa.] aa (ˈɑːɑː) n (Geological Science) a volcanic rock consisting of angular blocks of lava with a very rough surface [Hawaiian] aa abbreviation for ana1 AA abbreviation …

