The word 'kill' derives from the Irish 'cill', meaning a church or monastic cell, and sites bearing that prefix often predate the formalisation of parish burial in Ireland by many centuries. That this particular cill was set aside specifically for children places it in a tradition that persisted quietly across rural Ireland for generations.

These grounds were used for the burial of unbaptised infants, who were excluded from consecrated churchyards under Catholic practice until relatively recently. Known in Irish as 'cilliní', they tend to occupy marginal land, field corners, or old enclosures, and were rarely marked on official maps with the frankness that this one was. At Ballynakilla the site sits within pasture, enclosed by a low stone wall in a rectangular plan. Numerous grave markers have been recorded within it, concentrated particularly toward the western side of the enclosure. The markers themselves are typical of such places, modest stones rather than inscribed monuments, reflecting both the informality of the burials and the grief that surrounded them.