Umbilicus

n.	1.	(Anat.) 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; the belly button, in humans.
	2.	(Gr. & Rom. Antiq.) An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled.
	3.	(Bot.) The hilum.
	4.	(Zool.) A depression or opening in the center of the base of many spiral shells.
	5.	(Geom.) One of the foci of an ellipse, or other curve.

Noun

1.

umbilicus - scar where the umbilical cord was attached Synonyms: bellybutton, navel, omphalos, omphalus

axis, center, center of action, center of gravity, centroid, centrum, core, dead center, epicenter, heart, hub, kernel, marrow, medulla, metacenter, middle, nave, navel, nub, nucleus, omphalos, pith, pivot, storm center