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

Fluoride is a mineral that has been added to drinking water for generations to strengthen teeth and reduce cavities by replacing minerals lost during normal wear and tear, according to the Centers for Disease Control and Prevention. —Stephany Matat, Los Angeles Times, 15 May 2025

It is added to some dental products, such as toothpaste, to help prevent cavities. —Mary Kekatos, ABC News, 15 May 2025

His work far from finished, Jim is immediately instructed to reach into Royce’s open chest cavity and aid in the surgery. —Judy Berman, Time, 12 May 2025

Research from the 1990s suggests that fluoride in water cuts cavities by up to 25 percent in children; mid-20th century studies found reductions of up to 70 percent. —Saul Elbein, The Hill, 1 May 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