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 helps prevent cavities in teeth and can be found naturally in water — but at levels that are too low to offer any benefit to people. —Nathaniel Weixel, The Hill, 11 Apr. 2025

While almost all bodies of water contain the naturally-occurring mineral at some level, scientists discovered in the 1930s that upping the amount could boost public dental health and prevent cavities. —Cybele Mayes-Osterman, USA Today, 8 Apr. 2025

In 2015, 66 percent of children in the state between the ages of six and nine had at least one cavity. —Megha Satyanarayana, Scientific American, 4 Apr. 2025

In the past few years, studies of cities in Alaska and Canada have shown that communities that stopped fluoridation saw significant increases in children’s cavities when compared with similar cities that did not. —Tribune News Service, Twin Cities, 1 Apr. 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