Where does “būla” come from?

būla (Old High German) comes from Proto-Germanic būlǭ, from Proto-Indo-European bew- — "low-pitch humming noise".

Ancestry of “būla”, step by step

StepLanguageWordMeaning
1Proto-Germanicbūlǭswelling; bump; boil
2Proto-Indo-Europeanbew-"low-pitch humming noise"
Every word from Proto-Indo-European bew-Every word from Proto-Germanic būlǭ