A chest tomb is essentially a stone box tomb, its sides carved with decorative panels and its top originally capped with a flat cover slab called a mensa. This one measures 2.1 metres long and just under a metre wide, modest in scale but considered in its execution, and it now sits in situ on the east side of the north wall of the church's north transept, more or less where it was first placed.

The tomb is built from fossiliferous limestone, a stone dense with the traces of ancient marine life, and set on a chamfered plinth. The carving on its south and west panels depicts geometric church windows in the Decorated style, a Gothic architectural vocabulary that had its heyday in the thirteenth and fourteenth centuries but continued to inform stonework in Ireland well into the sixteenth. The motifs are crisp and precise, suggesting a mason who knew the tradition well. The east and rear sides are plain stone walls, indicating the tomb was always intended to sit against a corner or recess. The cover slab was absent when the tomb was excavated, but a separately recorded fragment of a mensa bearing the date 1543 may once have belonged to it, hinting at a slightly earlier origin or at least at a long history of use within the same building.