plaque

UK: /ˈplɑːk/ US: /plæk/ ,(plak)

WordReference Random House Learner's Dictionary of American English © 2025

plaque /plæk/   n. 

1. a thin, flat plate or tablet of metal, porcelain, etc., intended for ornament, as on a wall, or with writing on it, usually intended to honor someone, placed on a wall, building, or monument:
   [countable] He received a plaque for his twenty years of service.
2. Pathology [uncountable] an abnormal, hardened deposit on the inner wall of an artery.
3. Dentistry [uncountable] a soft, sticky, whitish film that forms on tooth surfaces.

WordReference Random House Unabridged Dictionary of American English © 2025

plaque  (plak), n. 

1. a thin, flat plate or tablet of metal, porcelain, etc., intended for ornament, as on a wall, or set in a piece of furniture.
2. an inscribed commemorative tablet, usually of metal placed on a building, monument, or the like.
3. a platelike brooch or ornament, esp. one worn as the badge of an honorary order.
4. Pathology, Anatomy [Anat., Pathol.] a flat, often raised, patch on the skin or other organ, as on the inner lining of arterial walls in atherosclerosis.
5. Dentistry a soft, sticky, whitish matlike film attached to tooth surfaces, formed largely by the growth of bacteria that colonize the teeth.
6. Microbiology, Laboratory [Bacteriol.] a cleared region in a bacterial culture, resulting from lysis of bacteria by bacteriophages.

• Middle Dutch placken to patch; compare placket
• French, noun, nominal derivative of plaquer to plate
• 1840–50

Collins Concise English Dictionary © HarperCollins Publishers::

plaque / plæk plɑːk/ noun

1. an ornamental or commemorative inscribed tablet or plate of porcelain, wood, etc
2. a small flat brooch or badge, as of a club, etc
3. any small abnormal patch on or within the body, such as the typical lesion of psoriasis
4. short for dental plaque

Etymology: 19th Century: from French, from plaquier to plate, from Middle Dutch placken to beat (metal) into a thin plate