Definition of "cavity"

A hole or hollow depression in a solid object.

1. (anatomy) A hollow area within the body.  examples

2. (engineering, manufacturing) The female part of a mold: the depression itself or (metonymically) the half of the mold that contains it.  examples

(dentistry) A small or large hole in a tooth caused by caries; often also a soft area adjacent to the hole also affected by caries.  examples