Where does “bulak-kahoy” come from?

bulak-kahoy (Tagalog) comes from Tagalog kahoy, from Proto-Philippine kahiw, from Proto-Malayo-Polynesian kahiw, from Proto-Austronesian kaSiw — wood; tree.

Ancestry of “bulak-kahoy”, step by step

bulak-kahoy traces back through two separate lines of ancestry.

via Tagalog kahoy

StepLanguageWordMeaning
1Tagalogkahoywood; lumber; wooden
2Proto-Philippinekahiwwood; tree
3Proto-Malayo-Polynesiankahiwwood; tree
4Proto-AustronesiankaSiwwood; tree

via Tagalog bulak

StepLanguageWordMeaning
1Tagalogbulakcotton
2Tagalogbukalspring of fresh water with continuous flow;...
Every word from Proto-Austronesian kaSiw