In Irish, a killeen, or cillín, refers to an unconsecrated burial ground, typically used for unbaptised infants, stillborn children, and occasionally suicides or others who, by the rules of the medieval and post-medieval Church, could not be interred in consecrated soil. These places occupy a peculiar position in the Irish landscape, neither fully sacred nor entirely forgotten, and the one at Killeens in County Kilkenny belongs to that sombre category of sites whose name is, in effect, its own monument.

Cilliní were in widespread use across Ireland from at least the early medieval period through to the twentieth century, and their distribution is particularly dense in the south and west of the country. The practice of burying the unbaptised apart from the community was bound up with theological doctrine around original sin, but the sites themselves were rarely chosen at random. Many were located near old church ruins, on parish boundaries, beside ancient earthworks, or at the edges of fields where the ground already carried some faint sense of age or otherness. The Kilkenny example, recorded under the placename Killeens, fits within this pattern, a locality whose very name signals the presence of such a burial place and suggests continuous local memory of what the ground once held.