Definitions
1.nounAny flat, thin piece of clay, ivory, metal, etc., used for ornament, or for painting pictures upon, as a dish, plate, slab, etc., hung upon a wall; also, a smaller decoration worn by a person, such as a brooch.
2.nounA piece of flat metal with writing on it, attached to a building, monument, or other structure to remind people of a person or an event.
3.nounA small card representing an amount of money, used for betting in casinos; a sort of gaming chip.
4.nounA clearing in a bacterial lawn caused by a virus.
5.nounIn the Hornbostel–Sachs classification system: any flat, thin musical instrument."blown plaques concussion plaques"
6.nounA broad patch of abnormal tissue distinguishable from surrounding tissue, especially a broad papule on the skin.
7.nounAn abnormal accumulation of material in or on an organ of the body, often associated with disease."amyloid plaque pleural plaque senile plaque"