Where does “wa” come from?

wa (Middle English) comes from Old English wā, from Proto-West Germanic wai, from Proto-Germanic wai, from Proto-Indo-European wai — oh!; woe!.

Ancestry of “wa”, step by step

wa traces back through two separate lines of ancestry.

via Old English wā

StepLanguageWordMeaning
1Old Englishwāwoe
2Proto-West Germanicwaiwoe!, alas!
3Proto-Germanicwaiwoe! alas!
4Proto-Indo-Europeanwaioh!; woe!

via Old English wǣ

StepLanguageWordMeaning
1Old Englishwǣ—
Every word from Proto-Indo-European wai →Every word from Proto-Germanic wai →Every word from Proto-West Germanic wai →