cavity

American  

[kav-i-tee] / ˈkæv ɪ ti /

noun

plural

cavities

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.

Related Words

See hole.

Other Word Forms

• cavitied adjective
• subcavity noun
• uncavitied adjective

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

The Melanoma Lung & liver cavity cancer will mean I will…

From Los Angeles Times • Apr. 13, 2026

In one case, a nest was discovered inside the pulp cavity of a sloth tooth.

From Science Daily • Apr. 3, 2026

The mass behind his eyeball grew into his nasal cavity and the side of his neck, he told The Times.

From Los Angeles Times • Mar. 30, 2026

The resonant cavity increases the local optical density of states and helps emitted light escape more efficiently.

From Science Daily • Mar. 24, 2026

They each had their own resting perches and each had a little shelter in a tree cavity to which they would fly when the day was over.

From "My Side of the Mountain" by Jean Craighead George

Related Words

• crater