cavity

American  

[kav-i-tee] / ˈkæv ɪ ti /

noun

• cavities
  plural

1. any hollow place; hollow.

2. Anatomy. a hollow space within the body, an organ, a bone, etc.

3. a hollow space or a pit in a tooth, most commonly produced by caries. A cavity may be artificially made to support dental restorations.

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cavity British  

/ ˈkævɪtɪ /

noun

1. a hollow space; hole

2. dentistry a soft decayed area on a tooth See caries

3. any empty or hollow space within the body

   the oral cavity

4. electronics See cavity resonator

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cavity Scientific  

/ kăv′ĭ-tē /

1. A hollow; a hole.

2. A hollow area within the body.

3. A pitted area in a tooth caused by caries.

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Usage

What is a cavity? A cavity is a pit or hole in a tooth caused by the decay of the enamel and bone, such as you might get if you don’t brush your teeth regularly. A cavity is more generally any hollow place or crater, as in When the old building was torn down, all that was left was a huge cavity in the ground. A cavity is also any other hole, divet, or pit in the body, such as the spinal cavity, which surrounds your spinal cord. Example: That cavity in your molar is probably from all the soda you drink.

Synonym Usage

See hole.

Other Word Forms

Derived Forms

• subcavity
  noun
• cavitied
  adjective
• uncavitied
  adjective

Inflected Forms

Nouns

• cavities
  plural

Etymology

Origin of cavity

First recorded in 1535–45; from Middle French cavite from Late Latin cavitās “hollowness,” equivalent to Latin cav(us) “hollow” + -itās -ity

Explanation

A cavity is a carved-out space inside something solid like a wall or a tooth. If you have a cavity, you have a hole in your tooth, and it’s time to go to the dentist for a filling. Lucky you. Doctors sometimes refer to various internal body parts as cavities, such as the "abdominal cavity," which includes the stomach and other hollow parts of the abdomen. You are more likely to hear the word at the dentist’s office, when she finds a cavity, which is a space in your tooth that's been eaten away by decay. Fun! (Not.) Cavity shares the Latin root cavus, "hollow," with the word cave.

Example Sentences

See Examples For:

cavity cavities

"Our calculations regard the concrete physical model of an atom that is placed in a cavity between two mirrors, where it can absorb and emit light particles," says postdoc Marcelo Janovitch.

From Science Daily ● Aug. 19, 2026

Potts and his collaborators had previously shown that photons leaving the cavity should not automatically be treated as "waste heat" in a thermodynamic description.

From Science Daily ● Aug. 19, 2026

Traditional cavity treatment usually involves removing damaged tooth material and placing a filling.

From Science Daily ● Jul. 29, 2026

Sensors, for example, could be placed in the oral cavity for real-time monitoring, continuously tracking changes in the oral environment and watch for things like markers of inflammation.

From The Wall Street Journal ● Jul. 26, 2026

So sweet, it’ll give you a cavity just thinking about it.

From "Booked" by Kwame Alexander

Those safe havens come in the form of nest boxes, specially designed to resemble the tree cavities barn owls nest in that are disappearing from our countryside.

From BBC ● Aug. 26, 2026

Untreated cavities send thousands of young children in the United States to emergency departments each year.

From Science Daily ● Jul. 29, 2026

After brain tumors are removed, a surgeon uses the tiles to line the walls of the empty cavities.

From The Wall Street Journal ● May 30, 2026

Police used planes, drones and thermal scanners in the investigation, the latter used "to detect concealed spaces and hidden cavities," they said.

From Barron's ● May 28, 2026

My Dictionary says cavernous means filled with cavities or hollow areas.

From "Mockingbird" by Kathryn Erskine

Related Words

• crater