Where does “open” come from?

open (Old Frisian) comes from Proto-West Germanic *opan, from Proto-Germanic upanaz, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

Ancestry of “open”, step by step

StepLanguageWordMeaning
1Proto-West Germanic*opanopen
2Proto-Germanicupanazopen
3Proto-Indo-Europeanupóunder, below
4Proto-Indo-Europeanh₃ewp-—
Every word from Proto-Indo-European h₃ewp- →Every word from Proto-Indo-European upó →Every word from Proto-Germanic upanaz →