Main Entry: plaque

Variant(s): also placque \ˈplak\

Function: noun

1 a : a localized abnormal patch on a body part or surface and especially on the skin <psoriatic plaque> b : a sticky usually colorless film on teeth that is formed by and harbors bacteria c : an atherosclerotic lesion d : a histopathologic lesion of brain tissue that is characteristic of Alzheimer's disease and consists of a dense proteinaceous core composed primarily of beta-amyloid that is often surrounded and infiltrated by a cluster of degenerating axons and dendrites—called also senile plaque
2 : a visibly distinct and especially a clear or opaque area in a bacterial culture produced by damage to or destruction of cells by a virus