[ plak , plα:k ]
■ noun
1》 an ornamental tablet fixed to a wall in commemoration of a person or event.
2》 a sticky deposit on teeth in which bacteria proliferate.
3》 Medicine a small, distinct, typically raised patch on or within the body, caused by local damage or deposition of material.
↘ Microbiology a clear area in a cell culture caused by the inhibition of growth or destruction of cells.
4》 a flat counter used in gambling.
Origin
C19: from Fr., from Du. plak 'tablet', from plakken 'to stick'.