Wiktionary
through-stone
n. (''Scottish and Northern English'') A horizontal slab acting as a gravestone
Usage examples of "through-stone".
Making straight for the steep cliff, where the churchyard hangs over the laneway to the East Pier so steeply that some of the flat tombstones, thruffsteans or through-stones, as they call them in Whitby vernacular, actually project over where the sustaining cliff has fallen away, it disappeared in the darkness, which seemed intensified just beyond the focus of the searchlight.