sacrarium

(historical)In Ancient Rome, a place where sacred objects were kept, either in a temple (the adytum) or in a house (holding the penates)

The area surrounding the altar of a Christian church; the sanctuary or piscina. Sometimes specifically a drain directly to the earth, perhaps including reference to a basin, for washing vessels from consecration.

2016, Martin Pousson, Black Sheep Boy, Los Angeles: Rare Bird Books, Part I, “Wanted Man,” The bathroom looked like a radiant sacristy, the sink a piscine, the drain a sacrarium.

(anatomy) The complex sacrum of any bird.