The name, which appears on the 1915 edition of the Ordnance Survey six-inch map, belongs to a cycle of folklore attached to the lovers Diarmuid and Gráinne, fugitives from the wrath of Fionn Mac Cumhaill, whose flight across Ireland was commemorated by attaching their story to megalithic monuments throughout the country. That a wedge tomb, one of the most common later Neolithic and early Bronze Age tomb types in Ireland, should carry such a name is not unusual; that this one sits on a valley slope with another wedge tomb visible roughly 300 metres to the north-west lends the landscape an unexpected density.

A wedge tomb is a type of megalithic structure characterised by a roofed stone chamber that is typically wider and higher at one end, tapering toward the other, the whole originally buried within a cairn or mound. The Termon example follows this pattern closely. The grass-covered mound measures approximately nine metres north to south and seven metres east to west, and within it the chamber, just under three metres long, widens and rises toward the south, which is also its entrance orientation. Both sidestones and the capstone remain in place, which puts this among the better-preserved examples in Clare. The upper edges of the sidestones have been dressed, and the capstone, 2.45 metres long and slightly trapezoidal, rests on the west sidestone at two points but on the east sidestone at only one. Ruaidhrí de Valera and Seán Ó Nualláin, who catalogued it as CL.22 in their 1961 Survey of the Megalithic Tombs of Ireland, noted a thin incised line running along the inside face of the east sidestone, close to its upper edge, which they interpreted as a later attempt to cut away a section of the stone. The east sidestone also leans slightly inward. A small recumbent stone at the south end may once have sealed the chamber entrance, and a possible packer stone survives just outside the same end.

The site sits within a north-south valley in the townland of Termon, and its position on the eastern slope means it faces west across the valley toward its near neighbour. Thomas Johnson Westropp, one of the more prolific recorders of Clare's antiquities in the late nineteenth and early twentieth centuries, initially placed the tomb in the wrong townland before correcting himself, a minor error that at least confirms the monument was known to fieldworkers well before modern survey work brought its measurements and condition into sharper focus.