Where does “*puku” come from?

*puku (Proto-Polynesian) comes from Proto-Oceanic *buku, from Proto-Austronesian *bukuh.

Ancestry of “*puku”, step by step

Step	Language	Word	Meaning
1	Proto-Oceanic	*buku	—
2	Proto-Austronesian	*bukuh	—

*puku — Etymology, Origin & Word History | Etymology Explorer