Dental Plaque and a Commemorative Plaque Share a Root
A plaque is a flat plate, and also a film of bacteria on teeth. Both come from a word meaning flat.
A plaque is a flat commemorative plate, and also a sticky film of bacteria on teeth. Medicine extends it further: arterial plaque is a fatty deposit on a vessel wall, and amyloid plaques are protein deposits in the brain. All share the sense of a flat layer, from a Dutch word meaning a flat plate or patch.
- A commemorative plate. *A blue plaque.*
- A film on teeth. *Remove plaque.*
- An arterial deposit. *Atherosclerotic plaque.*
- A patch on the skin. *A raised plaque.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | plaque | A bronze plaque. |
| Plural | plaques | Blue plaques. |
| Related | placard | A protest placard. |
| Related | plaquette | A small plaquette. |
| Related | tartar | Hardened tartar. |
How it is used in a sentence
- Blue plaques mark notable buildings.A London scheme since 1866.
- Plaque hardens into tartar.Which brushing cannot remove.
- Arterial plaque narrows blood vessels.Atherosclerosis.
Kinds of plaque
- Commemorative — a plate recording a person or event
- Dental — a biofilm of bacteria on teeth
- Tartar — plaque that has mineralised and hardened
- Atherosclerotic — fatty deposits inside arteries
- Amyloid — protein deposits associated with Alzheimer's disease
From French *plaque*, from Middle Dutch *placke*, a flat disc or patch. The medical senses date from the nineteenth century.
Plaque or tartar?
Plaque is a soft bacterial film that brushing removes. Tartar is mineralised plaque, which requires professional cleaning.
What are blue plaques?
Markers placed on buildings in Britain to record that a notable person lived or worked there. The scheme began in London in 1866.