plaque

n. 1 commemorative tablet, esp. Fixed to a building. 2 deposit on teeth where bacteria proliferate. [dutch plak tablet: related to *placard]

n. Any flat, thin piece of metal, clay, ivory, or the like, used for ornament, or for painting pictures upon, as a slab, plate, dish, or the like, hung upon a wall; also, a smaller decoration worn on the person, as a brooch.