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
The vibrating bristles of this electric version can break up and sweep away plaque more effectively.
—
Nicol Natale, PEOPLE, 28 Dec. 2025
In atherosclerosis, fatty deposits called plaques build up in arteries.
—Cory Martin, Verywell Health, 28 Dec. 2025
On the outside walls, there are blue plaques in honour of the two former landlords — Jack Borthwick, 1921-26 and 1938-42, and Norman Greenhalgh, 1951-56 — who had previously played for Everton.
—Daniel Taylor, New York Times, 24 Dec. 2025
At the White House, the president made an effort to literally rewrite history, installing plaques underneath the portraits of past presidents with overtly political and often false descriptions of his predecessors.
—ABC News, 21 Dec. 2025
See All Example Sentences for plaque
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Nicol Natale, PEOPLE, 28 Dec. 2025
In atherosclerosis, fatty deposits called plaques build up in arteries.
—Cory Martin, Verywell Health, 28 Dec. 2025
On the outside walls, there are blue plaques in honour of the two former landlords — Jack Borthwick, 1921-26 and 1938-42, and Norman Greenhalgh, 1951-56 — who had previously played for Everton.
—Daniel Taylor, New York Times, 24 Dec. 2025
At the White House, the president made an effort to literally rewrite history, installing plaques underneath the portraits of past presidents with overtly political and often false descriptions of his predecessors.
—ABC News, 21 Dec. 2025
See All Example Sentences for plaque
Cite this Entry
“Plaque.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/plaque. Accessed 29 Dec. 2025.
Copy CitationKids Definition
plaque
noun1
: 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
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
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