plate

A plate is a flat dish used for serving or eating meals. Plates are produced in a range of sizes and shapes, typically circular. Materials include porcelain, ceramic, glass, metal, and plastic. The term derives from Old French plat, from Latin planus meaning flat. In many cultures, plates are part of tableware sets and may be decorative or functional. In historical contexts, plates were originally made from pottery, metal, or wood; industrial production and mass availability emerged in the 18th-19th centuries.

In geology, a plate refers to one of several large, rigid segments of the Earth's lithosphere. Each plate comprises the crust and the rigid upper mantle, and moves relative to others due to convection in the mantle. Major plates include the Pacific, North American, and Eurasian Plates. Plate boundaries are sites of seismic and volcanic activity and can be divergent, convergent, or transform. The theory of plate tectonics, consolidated in the mid-20th century, explains continental drift and many geologic phenomena.

In biology, platelets are small, anucleate cell fragments essential for blood clotting. In humans they derive from megakaryocytes in the bone marrow and circulate in the bloodstream for about 7–10 days. Platelets adhere to damaged vessels, aggregate, and release chemical factors that promote coagulation and wound healing. In non-mammals, similar cells called thrombocytes perform analogous functions.

In dentistry, a plate can refer to a removable denture or dental plate, a prosthetic device used to replace missing teeth and support soft tissues.