A diverticulum (plural: diverticula) is the medical or biological term for an outpouching of a hollow (or a fluid-filled) structure in the body. Depending upon which layers of the structure are involved, they are described as being either true or false.
In medicine, the term usually implies the structure is not normally present. However, in the embryonic stage, some normal structures begin development as a diverticulum arising from another structure.
Read more about Diverticulum: Anatomical, Classification, Pathological, Embryological