The Irish "Cill" denotes a church or burial ground, and the second element likely preserves the name of an early Christian saint or founder, now largely forgotten. That combination, a named saint, a lost church, a persisting graveyard, is a pattern repeated across the west of Ireland, where early medieval ecclesiastical sites were often modest enough to leave little above the ground yet durable enough to keep drawing the dead for centuries.

Beyond the name itself, the documentary record for this particular site is thin. What can be said with confidence is that graveyards bearing the "Kil" prefix tend to mark early Christian foundations, often dating to the period between the sixth and ninth centuries, when wandering monks and local lords together shaped the religious landscape of Connacht. In many such places the church building has long since vanished, leaving only the consecrated ground and, sometimes, fragments of worked stone or the curved boundary of an ancient enclosure. Whether any such features survive at Killaan is not currently established in the available record.