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

Incorporating xylitol gum into your dental routine reduces plaque accumulation and cavity formation. —Amy Brownstein, Verywell Health, 1 Aug. 2025

This erosion can weaken teeth over time, increasing their vulnerability to cavities and discomfort. —Lucy Notarantonio, MSNBC Newsweek, 12 July 2025

This pink toothpaste works over time to remove stains (and prevent them), whiten teeth, prevent cavities, and freshen your breath. —Katie Decker-Jacoby, StyleCaster, 10 July 2025

These thin coatings applied to the chewing surfaces of molars are proven to prevent up to 80% of cavities. —Olga Ensz, The Conversation, 30 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