Possibly derived from Proto-Yoruboid *é-ji or Proto-Yoruboid *á-ji. Cognate with Igala áji (“river, stream, any type of body of water”) and Arigidi edʒĩ (“water”), Arigidi ùdʒi, Aja (West Africa) eji, Fon jĭ (“rain”), likely originally served as a synonym for water or any water-related noun in Proto-Yoruboid before becoming defined more narrowly. The root verb "ji" may be cognate with Nupe jè (“to flow, to run (as water)”), compare with Nupe èjè (“current, tide of water”), possibly from the root Proto-Niger-Congo *-gi (“water”)