Receptacles of various types that contain holy relics. Usage has varied over time. In modern usage, the term refers to relatively small disc-shaped, glass-faced metal receptacles for relics, often designed so that they may be inserted into reliquary monstrances. In Early Christian usage, the term referred to cells or openings dug into walls to hold the corpse. For discs or clips that secure a host in a monstrance, use "lunettes (monstrance clips)."