Where does “ehu” come from?

ehu (Maori) comes from Proto-Polynesian *efu, from Proto-Oceanic *qapu, from Proto-Malayo-Polynesian qabu, from Proto-Austronesian qabu — ash.

Ancestry of “ehu”, step by step

StepLanguageWordMeaning
1Proto-Polynesian*efuash solid remains of a fire
2Proto-Oceanic*qapuash solid remains of a fire
3Proto-Malayo-Polynesianqabuash solid remains of a fire
4Proto-Austronesianqabuash
Every word from Proto-Austronesian qabu →Every word from Proto-Malayo-Polynesian qabu →Every word from Proto-Oceanic *qapu →