Where does “aa” come from?

aa (English) comes from Ancient Greek ἀνά, from Proto-Hellenic *aná — up, upon.

Ancestry of “aa”, step by step

aa traces back through two separate lines of ancestry.

via Ancient Greek ἀνά

StepLanguageWordMeaning
1Ancient Greekἀνάon board; on, upon
2Proto-Hellenic*anáup, upon

via Hawaiian ʻaʻā

StepLanguageWordMeaning
1Hawaiianʻaʻāaa, a type of lava; to burn, glow; to be covered...
2Proto-Polynesiankakaha—
Every word from Proto-Hellenic *aná →
aa — Etymology, Origin & Word History | Etymology Explorer