کو- (Rumi spelling ku-, Informal, rough even towards older people)
From کو, shortened form of اکو, from Proto-Malayic *aku, from Proto-Malayo-Chamic *aku, from Proto-Malayo-Sumbawan *aku, from Proto-Sunda-Sulawesi *aku, from Proto-Western Malayo-Polynesian *aku, from Proto-Malayo-Polynesian *aku, from Proto-Austronesian *aku.