any hollow place; hollow.

Anatomy . a hollow space within the body, an organ, a bone, etc.

a hollow space or a pit in a tooth, most commonly produced by caries. A cavity may be artificially made to support dental restorations.

noun

atrium , basin , bursa , caries , chamber , crater , decay , dent , depression , gap , hole , hollow , pit , pocket , sinus , socket , vacuity , void , antrum , bag , cave , cavern , excavation , grotto , mine , orifice , sac , sink , vacuum , vein , vesicle