umbilicus > define

noun

• A scar where the umbilical cord was attached.
  • usage: "you were not supposed to show your navel on television"; "they argued whether or not Adam had a navel"; "she had a tattoo just above her bellybutton"
  • synonyms: navel, bellybutton, belly button, omphalos, omphalus

• (n.) The hilum.
• (n.) A depression or opening in the center of the base of many spiral shells.
• (n.) The depression or mark, in the median line of the abdomen, which indicates the point where the umbilical cord separated from the fetus; the navel.
• (n.) Either one of the two apertures in the calamus of a feather.
• (n.) One of foci of an ellipse or other curve.
• (n.) A point of a surface at which the curvatures of the normal sections are all equal to each other. A sphere may be osculatory to the surface in every direction at an umbilicus. Called also umbilic.
• (n.) An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled.