plaque
n. C / Un. a sticky film of bacteria that grows on your teeth, or a flat sign on a wall that honors a person or event.
n. a biofilm of bacteria and food particles that adheres to the surface of teeth; also, a flat plate of metal or stone fixed to a surface as a memorial.
Brushing your teeth helps remove plaque.
The city council installed a bronze plaque to mark the house where the famous poet once lived.
If left untreated, dental plaque can mineralize into tartar, while arterial plaque buildup can lead to serious cardiovascular complications by narrowing the blood vessels.
Unadapted borrowing from French plaque (“plate, sheet (of metal); slab (of marble); bacteria on teeth”), from French plaquer, Middle French 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 plaggą (“patch”). The word is cognate with Middle Low German placke, plagge (“small stain, scraps, rags, thin grass”), German Placken (“spot, patch”), Saterland Frisian plak, plakke (“a blow, slap”), Swedish plagg (“clothing, garment”). Compare plack.
Uncountable when referring to the biological substance on teeth or in arteries; countable when referring to a commemorative sign.