From Proto-Polynesian *ŋalu (“mounting wave, ocean wave”) (compare with Hawaiian nalu, Tahitian ʻaru, Tongan ngalu, Samoan galu), from Proto-Oceanic *ŋalun (“mountain wave”), from Proto-Malayo-Polynesian *qalun (“long rolling wave; swell”) (compare with Malay alun, Tagalog alon).