OMPHALOS

navel, umbilicus, bellybutton, belly button, omphalos, omphalus

(noun) a scar where the umbilical cord was attached; “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”

Source: WordNet® 3.1

Etymology

Noun

omphalos (plural omphaloi)

An ancient religious stone artifact, or baetylus, used to denote the direction of the "center" of the world.

The theological proposition that the world was created with certain indicia of a history which had not actually occurred (such as the humans who had never been connected to umbilical cords being created with navels).

The navel.

A raised central point; a boss.

The center or hub.

Source: Wiktionary

Om"pha*los, n. Etym: [L., fr. Gr. (Anat.)

Definition: The navel.

Source: Webster’s Unabridged Dictionary 1913 Edition