Question

what is the definition of cavity??

Answer 1

a decayed part of tooth is known as cavity

Answer 2

A cavity is a hole that can grow bigger and deeper over time. Cavities are also called dental caries (say: KARE-eez), and if you have a cavity, it's important to get it repaired. But why would your tooth develop a hole? Blame plaque. That's a sticky, slimy substance made up mostly of the germs that cause tooth decay.