Where does “bāzu” come from?

bāzu (Old Persian) comes from Iranian *bājus, from Proto-Indo-Iranian bʰaHȷ́ʰúš, from Proto-Indo-European bʰāǵʰus — arm.

Ancestry of “bāzu”, step by step

StepLanguageWordMeaning
1Iranian*bājus—
2Proto-Indo-IranianbʰaHȷ́ʰúšarm
3Proto-Indo-Europeanbʰāǵʰusarm
Every word from Proto-Indo-European bʰāǵʰus →Every word from Proto-Indo-Iranian bʰaHȷ́ʰúš →Every word from Iranian *bājus →