1. 匾额；饰板
A plaque is a flat piece of metal or stone with writing on it which is fixed to a wall or other structure to remind people of an important person or event.

2. 牙斑；齿菌斑
Plaque is a substance containing bacteria that forms on the surface of your teeth.

1. a memorial made of brass

Synonym: brassmemorial tablet

2. (pathology) a small abnormal patch on or inside the body