The slab is recumbent and intact, measuring 1.83 metres in length and tapering from 0.6 metres at the head to 0.4 metres at the base, with chamfered edges and a Latin cross carved in false relief. That technique, sometimes called false or sunk relief, involves cutting away the background so that the design appears raised without actually being worked in three dimensions. The cross divides the surface into four panels; the two small square panels between the arms of the cross are filled with interlace ornament, the knotwork patterning associated with early medieval Irish stonework. On the right side of the shaft, an incised Latin inscription reads, tentatively, "hic jacet Hugo O Ranůn", meaning "here lies Hugh O'Ranun", though the surname is uncertain. The panel on the left side of the shaft was left blank.

The slab sits 2.8 metres south of the ruined church at Lackan, itself a nave-and-chancel structure built on ground with a much longer sacred history. The Annals of Ulster record the death in 750 of Fursu, abbot of Lecan Midhe, placing an Early Christian monastery here well over a millennium ago. The site's ecclesiastical importance continued into the medieval period: during the reign of Edward I, between 1272 and 1307, a man named Adam de Ledwyche granted the church of Lackan to the Abbey of Tristernagh, an Augustinian house also in Co. Westmeath. The graveslab, located immediately south of the Delamere family burial plot and immediately east of a Celtic Cross marking the grave of Patrick Wallace, belongs to this layered landscape where early monastic, medieval, and post-medieval burial practices have accumulated on the same rising ground.