plaque
n
flat (usu round) piece of stone, metal or porcelain fixed on a wall as an ornament or a memorial (装於墙上作饰物或纪念物的石质、 金属或瓷制的)饰板(通常为圆形)
A simple plaque marks the spot where the martyr died. 有一块朴素的饰板用以纪念该烈士的殉难处.
plaque n [U]
(medical 医) soft substance that forms on teeth and encourages the growth of harmful bacteria 牙斑
It is necessary to remove plaque by brushing one´s teeth. 需刷牙以去除牙斑. Cf 参看 tartar1 1.