Noun (countable and uncountable, plural plaques)
- 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.
- A piece of flat metal with a writing on it, atached to a building to remind people of a person ar an event
- (uncountable) An accumulation of biofilm, or bacteria on teeth.
- (uncountable, medicine) Atheroma, an accumulation in artery walls made up of macrophage cells and debris containing lipids, (cholesterol and fatty acids), calcium, and connective tissue.
- (biology) A clearing in a bacterial lawn caused by a virus.
Origin Borrowing from French plaque, derivative of plaquer (“to plate"), from Middle Dutch placken (“to patch, beat metal into a thin plate"), from placke (“disk, patch, stain"), from Old Dutch *plagga (“patch"), from Proto-Germanic *plaggÄ… (“patch"). Cognate with Middle Low German placke, plagge (“small stain, scraps, rags, thin grass"), German Placken (“spot, patch"), Eastern Frisian plak, plakke (“a blow, slap"), Swedish plagg (“clothing, garment"). See plack.
