The navel or belly button, which is the scar on the abdomen at the site of the former attachment of the umbilical cord. The doctor examined the newborn's umbilicus to ensure it was healing properly.
A central point or middle part, often used metaphorically to describe a focal point. The ancient city was considered the umbilicus of the empire, connecting various trade routes.
In zoology, especially malacology, a funnel-shaped hollow at the axis of a coiled gastropod shell. The wide umbilicus of the snail’s shell makes the species easy to identify.