A chest tomb, sometimes called an altar tomb, is a raised box-shaped monument with a flat ledger stone on top, common in post-Reformation Irish and English funerary practice. This one, however, does not quite hold together. The ledger on top does not match the sides either in size or carving style, and the fluted capitals decorating the ledger's north face are inconsistent with the Ionic columns on the side panels. The working conclusion among researchers is that two originally separate monuments were combined into one structure sometime after 1700, giving the tomb an assembled, composite quality that sets it apart from more straightforward examples of the type.

The tomb came to light only in 2012, during a graveyard recording and clean-up scheme, having apparently gone unrecorded before that point. It is possibly associated with the Brown family, and the Knockainy Historical and Conservation Society has suggested that Sir Thomas Browne of Hospital, who built the chancel of St. John's Church in 1615, may have been responsible for commissioning the altar tomb. The north-facing side panel is the most visually elaborate face of the monument. On its eastern half, a carved Crucified Christ is flanked by the words ECCE HOMO, with INRI above the cross and a banner inscription beneath reading MEDIUM TENUERE BEATI, tentatively translated as "Blessed are those who keep a middle course." The date 1618 appears below the crucifixion scene. To the west of that panel sits an armorial-style shield bearing the IHS monogram with a cross, surrounded by Latin text. The ledger itself carries incised lettering including the partial phrase NCIPI FIEDLIS AMPLE PROLES, with the word PARENS continuing around the western edge. The initials E.B. and MFD appear within carved roundels, and K.G. and E.B. are visible on the end panels. A Latin inscription running along the base is only partially legible, reading in part "Ecce Modo......Generous Erat."

The graveyard at Knockainy West is the place to look, with the tomb recorded under the Sites and Monuments Register reference LI032-141005-. The south face of the monument is not currently visible and appears to be partially damaged, so the north side, with its carved panels and columns, is where the detail rewards close attention. The inscriptions are worn in places, and some text remains fragmentary or uncertain in its reading, which gives the monument an unresolved quality that the composite structure only reinforces.