A bullaun is a large stone, usually boulder-sized, into which one or more cup-shaped depressions have been ground, either by human hand or, in some cases, by natural weathering processes. The water that collects in these hollows has long been considered to have curative or protective properties, and bullauns are frequently found close to early church sites, holy wells, and places associated with local saints. Whether they served a liturgical function, a folk-medicine one, or something older still is a question that remains open.

The place-name Cill Ogúla points to an early Christian foundation, with "cill" being the Irish word for church or monastic cell, appearing throughout early medieval topography wherever a small religious community once settled. The second element likely refers to a personal name, suggesting the site was associated with a particular saint or founder, though the precise identity of Ogúla is not well documented in surviving sources. This kind of named dedication was common in the early Irish church, where local saints presided over local landscapes in a way that left traces in placenames long after the physical structures they once knew had disappeared or been replaced.