The slab, recorded as decorated with a cross in relief, carries a Latin inscription in raised Roman characters that survives only partially. What remains reads: HIC JACET THADEUS GEANKAGH O'MEAGHER GENEROSUS QUI ORBIT 19 DECEMBRIS A.D. 1627 CUJUS AIAE PROPITIETUR DEUS, a conventional memorial formula meaning roughly "Here lies Thadeus Geankagh O'Meagher, gentleman, who died 19 December AD 1627, may God be merciful to his soul." The slab is physically present in the graveyard, or at least was when first noted, but its precise location within the site has never been established.

The inscription was recorded in the mid-nineteenth century by Brennan, writing in the 1850s, who identified the man commemorated as belonging to the O'Meagher family, a Gaelic sept with deep roots in Tipperary. The Latin word generosus, used here, was a common honorific on early modern Irish gravestones, denoting a man of gentle or noble birth. A second graveslab in the same churchyard, dated to the 16th or 17th century, survives in a more locatable position, immediately to the north of the eastern end of the south wall of the ruined medieval church. This second slab carries its own inscription, though it has worn beyond legibility. The two stones together suggest that the graveyard was a site of some social significance, used by families who wished their status marked in both language and stone, even as the carved lettering slowly gave way to weathering and time.