Diploë is a term used in anatomy, and it refers to the spongy tissue that lies between the outer and inner layers of bones in the skull. Synonyms for the word diploë include cancellous bone, spongy bone, and trabecular bone. Cancellous bone is the softer, spongy bone that supports the harder cortical bone in the structure of the skeleton. Spongy bone is found in a variety of bones, including the spinal column, ribs, and pelvis. Trabecular bone is a type of spongy bone that is found in the ends of long bones, such as the leg bones and arm bones. All of these terms refer to the same tissue that serves as a cushion between the layers of bone in the skull.