Somewhere in the records of County Waterford's early medieval landscape, a bullaun stone has gone missing. A bullaun is a rounded boulder, typically of some antiquity, into which one or more cup-shaped depressions have been deliberately ground, most likely used for grinding or crushing, though many became associated with holy wells and votive practice over the centuries. The example from Kilmacomb is notable less for what it is than for the fact that it is no longer where it should be: removed, at some point, from the parish church of Kilmacomb, its current whereabouts unrecorded.

The stone was associated with the ruined church at Kilmacomb, a site sitting towards the bottom of a south-facing slope. Its removal was noted in nineteenth-century antiquarian literature, with references appearing in the work of Reverend G. H. Reade, writing in the late 1860s, and Reverend P. Power, whose survey of the ancient ruined churches of County Waterford was published around 1890 to 1891. Both writers seem to have caught the stone at a moment when its displacement was already a matter of record rather than fresh observation, which suggests the removal may have occurred well before either account was written. The qualifying word "possible" attached to its identification adds a further layer of uncertainty: whether the object was a true bullaun, a natural glacial hollow, or something else entirely was perhaps never firmly settled.