The term "ribcage" refers to a person's rib cage, which is the part of the body that contains and protects the vital organs such as the heart and lungs. It consists of 12 pairs of ribs connected by their ends to the spine at the backbone in the thoracic cavity. The ribcage provides support for the upper body, protection for internal organs, and helps with breathing through its connection to the diaphragm muscle which aids in respiration.