Where does “bofratino” come from?

bofratino (Esperanto) comes from Esperanto frato, from Latin frāter, from Proto-Italic frātēr, from Proto-Indo-European bʰréh₂tēr — brother.

bofratino (Esperanto): sister-in-law

Definitions

Step	Language	Word	Meaning
1	Esperanto	frato	brother; sibling
2	Latin	frāter	—
3	Proto-Italic	frātēr	brother
4	Proto-Indo-European	bʰréh₂tēr	brother

bofratino — Etymology, Origin & Word History | Etymology Explorer