The name Lagakilleen carries within it the Irish element "cill", meaning a small church or monastic cell, a word that appears across Irish placenames wherever early Christian communities once settled. That linguistic trace is often all that survives in places like this, where the physical remains may amount to little more than a grassy enclosure, a scatter of stone, or a low outline visible only at certain times of year when the light falls at an angle across the ground.

Sites bearing the "cill" element in their names frequently date to the early medieval period, roughly the sixth to twelfth centuries, when Ireland was covered by a network of small ecclesiastical foundations, many of them associated with local saints whose names have long since faded from wider memory. Some of these sites continued in use as parish churches into the later medieval period; others were abandoned early and left to become the kind of quietly persistent feature in the countryside that neither fully disappears nor fully declares itself. Without more detailed records currently available for Lagakilleen specifically, the full history of this particular site, its dedication, its extent, and what fabric if any survives, remains to be established.