Proposed to derive from Proto-Yoruboid *á-jà (“village, homestead”), cognate with Olukumi ọzà (“market”), Igala ájà (“residence. compound, homestead, settlement”), Itsekiri aja (“village”), Ifè adzà (“market”), where the semantic meaning shifted from "village," "homestead," or "home" to market, likely as towns grew bigger and markets became a feature of an established town. This semantic meaning seems to still exist in compound terms like ọlọ́jà (“king”), literally meaning "ruler of the town." The semantic shift may have appeared after the split of Itsekiri from Proto-Edekiri. Likely related to Igala ájá (“market”)