Where does “bōbô” come from?

bōbô (Proto-Germanic) comes from Proto-Germanic bō-, from Proto-Indo-European bʰā- — to say.

Ancestry of “bōbô”, step by step

Step	Language	Word	Meaning
1	Proto-Germanic	bō-	A stem meaning "father, brother, close male...
2	Proto-Indo-European	bʰā-	to say