An altar-slab; the consecrated slab or block of stone constituting an altar. See altar, 2.(noun)
The Century Dictionary (Public Domain)
Use "altar-stone" in a sentence
"The altar-stone, once thought to be porphyry, is more likely to be a variety of Purbeck marble."
"Quick soft hands lifted her and laid her on the altar-stone amidst a bed of flowers."
"Xaltotun stood beside the dark altar-stone and stared across the valley, at the dead and wounded men on the terraces, at the grim, blood-stained band at the head of the slopes, at the dusty, steel-clad ranks reforming in the vale below."