cavity

noun

cav·​i·​ty ˈka-və-tē 

plural cavities

1

: an unfilled space within a mass

especially : a hollowed-out space

2

: an area of decay in a tooth : caries

Synonyms

• concavity
• dent
• depression
• dint
• hole
• hollow
• indentation
• indenture
• pit
• recess

Examples of cavity in a Sentence

Some birds nest in tree cavities.

I had two cavities filled at the dentist's.

Recent Examples on the Web

It is added to some dental products, such as toothpaste, to help prevent cavities. —Mary Kekatos, ABC News, 2 Apr. 2025

Fluoride strengthens teeth and reduces cavities by replacing minerals lost during normal wear and tear, according to the U.S. Centers for Disease Control and Prevention. —Matthew Brown and Hannah Schoenbaum, Los Angeles Times, 28 Mar. 2025

And, a wealth of studies have found that water fluoridation was related to a significant (up to 30%) decrease in cavities among adults and children. —Mary Walrath-Holdridge, USA Today, 28 Mar. 2025

Brushing your teeth twice a day for two minutes with fluoride toothpaste helps reduce the risk of cavities (caries) and periodontal disease. —Sherri Gordon, Health, 26 Mar. 2025

Word History

Etymology

borrowed from Middle French & Late Latin; Middle French cavité, borrowed from Late Latin cavitāt-, cavitās, from Latin cavus "hollow, concave" + -itāt-, -itās -ity — more at hole entry 1

First Known Use

1541, in the meaning defined at sense 1

Phrases Containing cavity

• abdominal cavity
• body cavity
• pelvic cavity
• segmentation cavity
• spinal cavity
• thoracic cavity

Rhymes for cavity

• gravity
• concavity
• depravity
• intracavity
• microgravity
• supergravity

Kids Definition

cavity

noun

cav·​i·​ty ˈkav-ət-ē 

plural cavities

1

: a hollow place

especially : an unfilled bodily space

lung cavity

2

: a hole hollowed out in a tooth by decay

Medical Definition

cavity

noun

cav·​i·​ty ˈkav-ət-ē 

plural cavities

1

: an unfilled space within a mass

2

: an area of decay in a tooth : caries