cav ‧ i ‧ ty /ˈkævəti, ˈkævɪti/ BrE AmE noun ( plural cavities ) [countable]
[ Date: 1500-1600 ; Language: French ; Origin: cavité , from Late Latin cavitas , from Latin cavus ; ⇨ ↑ cave 1 ]
formal a hole or space inside something:
Put herbs inside the body cavity of the fish.
I have no cavities (=no holes in my teeth) .