These grounds, known in Irish as cillíní (singular cillín), were used for the interment of unbaptised infants, and sometimes others considered outside the formal rites of the Catholic Church, including stillborn children, and occasionally suicide victims or strangers. Because the Church denied them consecrated ground, families buried these children in marginal spaces: old ringforts, coastal strands, field boundaries, and the ruins of early medieval ecclesiastical sites. The practice continued in some areas well into the twentieth century.

The Kilcolumb site carries that same weight of quiet exclusion. The place-name itself suggests an early Christian association, likely deriving from the Irish for "church of Colm" or a similar dedication, hinting that the location may once have been connected to an early ecclesiastical enclosure of the kind that frequently attracted later cillín burials. Families chose such spots partly from practicality and partly from a folk belief that the sanctity lingering in ancient ground might offer some protection or blessing to children who had been refused it officially. The graves themselves are typically unmarked, or marked only with small stones, and the sites are often difficult to identify without local knowledge.