plaque

noun

ˈplak 

1

a

: an ornamental brooch

especially : the badge of an honorary order

b

: a flat thin piece (as of metal) used for decoration

c

: a commemorative or identifying inscribed tablet

2

a

: a localized abnormal patch on a body part or surface

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

3

: a clear area in a bacterial culture produced by viral destruction of cells

Examples of plaque in a Sentence

A bronze plaque marked the city's oldest building.

They gave him a plaque in honor of his 30 years of service.

Brushing your teeth prevents the buildup of plaque.

The scientists are studying the way the plaques form.

Recent Examples on the Web

His Hall of Fame plaque was displayed at home plate during the ceremony. — Gabriel Burns, AJC.com, 31 July 2026

Visitors begin not by reading a plaque, but by pulling out their smartphones. — Jasmine Baehr, FOXNews.com, 29 July 2026

One is a coronary artery calcium scan, a specialized CT scan that looks for calcified plaque in the arteries supplying the heart. — Katia Hetter, CNN Money, 27 July 2026

The design-forward Saint Laurent Rive Droite x Fieldbar Gin Trunk features a hardcase cooler box with a custom, individually numbered Saint Laurent plaque, the company shared with Travel + Leisure. — Alison Fox, Travel + Leisure, 27 July 2026

Word History

Etymology

French, from Middle French, metal sheet, from plaquer to plate, from Middle Dutch placken to piece, patch; akin to Middle Dutch placke piece, Middle High German placke patch

First Known Use

1845, in the meaning defined at sense 1a

Phrases Containing plaque

• anti-plaque

Rhymes for plaque

• ack
• brack
• clack
• crack
• dak
• flack
• flak
• hack
• jack
• knack
• lac
• lack

Kids Definition

plaque

noun

ˈplak 

1

: an ornamental pin

especially : an honorary badge

2

: a flat thin piece (as of metal) used for decoration or inscribed as a memorial or marker

3

: a sticky usually colorless film on teeth that is formed by and contains bacteria

Medical Definition

plaque

noun

variants also placque

ˈplak 

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