Where does “jet” come from?

jet (Old Frisian) comes from Proto-West Germanic gat, from Proto-Germanic gatą, from Proto-Indo-European gʰodom.

Ancestry of “jet”, step by step

StepLanguageWordMeaning
1Proto-West Germanicgathole, opening
2Proto-Germanicgatąhole, opening, passage
3Proto-Indo-Europeangʰodom—
Every word from Proto-Indo-European gʰodom →Every word from Proto-Germanic gatą →Every word from Proto-West Germanic gat →