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

• 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

Thanks to fluoridated water, childhood and adult cavities have been reduced by about 25%. —Samantha Korn, Sun Sentinel, 24 June 2025

Each of those frequencies creates its own quantum resonator in the same cavity, with its own set of modes. —John Timmer, ArsTechnica, 6 June 2025

Water fluoridation is another preventative policy that saves money: In 2024, the CDC estimated that providing communities with fluoridated water for one year saves $6.5 billion in dental treatment costs and leads to 25% fewer cavities. —Alana Semuels, Time, 5 June 2025

From obesity to cavities, doctors and health experts have warned against high sugar intake for decades. —Irene Wright, Miami Herald, 3 June 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