Where does “ater” come from?

ater (Middle English) comes from Old English ātor, from Proto-Germanic *aitr, from Proto-Germanic aitrą, from Proto-Indo-European h₂oyd- — abscess; tumor, abscess.

Ancestry of “ater”, step by step

StepLanguageWordMeaning
1Old Englishātorpoison
2Proto-Germanic*aitr—
3Proto-Germanicaitrąpoison; pus
4Proto-Indo-Europeanh₂oyd-abscess; tumor, abscess
Every word from Proto-Indo-European h₂oyd- →Every word from Proto-Germanic aitrą →Every word from Proto-Germanic *aitr →