Cavity and Thoracic cavity

Cavity noun - A sunken area forming a separate space.

Thoracic cavity and cavity are semantically related. In some cases you can replace phrase "Thoracic cavity" with "Cavity", this terms are similar.

Thoracic cavity noun - The cavity in the vertebrate body enclosed by the ribs between the diaphragm and the neck and containing the lungs and heart.

Cavity and thoracic cavity are semantically related. You can use "Cavity" instead a noun phrase "Thoracic cavity".