Where does “eifer” come from?

eifer (Middle High German) comes from Old High German eivar, from Proto-Germanic aibraz, from Proto-Indo-European h₂eybʰros — sharp, severe, astringent.

Ancestry of “eifer”, step by step

StepLanguageWordMeaning
1Old High Germaneivarsour", "acidic
2Proto-Germanicaibrazsharp, bitter; vehement, dire; violent
3Proto-Indo-Europeanh₂eybʰrossharp, severe, astringent
Every word from Proto-Indo-European h₂eybʰros →Every word from Proto-Germanic aibraz →Every word from Old High German eivar →