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 of cavity

• hole
• dent
• pit
• concavity

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

This cavity extends to the trunk at the foot of the bed, where the Spirit of Christmas Present will soon materialize. —Teri Sforza, Oc Register, 4 Dec. 2025

Your mouth is also home to other bacteria that compete with cavity-causing bacteria for resources and space, fighting them off and restoring the acidity of your mouth to levels that aren’t harmful to teeth. —Jacqueline Abranches, The Conversation, 2 Dec. 2025

It was first rolled out in Grand Rapids, Michigan, in January 1945, after evidence showed that having a trace amount in water could dramatically lower tooth decay and cavities. —New Atlas, 30 Nov. 2025

The kestrels use tree cavities and other small spaces to raise their chicks and were quick to move into the orchards. —Laura Baisas, Popular Science, 27 Nov. 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