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.

---

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

---

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.

---

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

“She could be in a cavity, or gap — in an air bubble. It could be. Miracles do happen. One cannot lose hope.”

From Los Angeles Times ● Jun. 30, 2026

A surgeon from the University of Texas MD Anderson Cancer Center removed her brain tumor and lined the cavity with the implants in late November 2022.

From The Wall Street Journal ● May 30, 2026

The researchers created a revised model that combines two important factors: the rapid evolution of light inside the laser cavity and the slower changes occurring in the laser's energy supply.

From Science Daily ● May 21, 2026

They repeatedly grow and shrink during successive trips through the laser cavity, creating a rhythmic oscillation that resembles breathing.

From Science Daily ● May 21, 2026

“Please. You ate more sugar than any kid in history, and you still got pearly whites, don’tcha? Just one cavity your entire life.”

From "As Brave As You" by Jason Reynolds

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

But employees like Derek aren’t quite as generous with their diagnosis: “They are getting cavities in their brains.”

From Slate ● Apr. 9, 2026

In testing, the artificial saliva spray reduced bacterial activity and slowed tooth demineralization -- the process by which teeth lose calcium and phosphate, making them more vulnerable to cavities.

From Science Daily ● Apr. 5, 2026

He understood that they were only animated cavities full of jelly and strings and liquids.

From "Snow Falling on Cedars: A Novel" by David Guterson

Related Words

• crater