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.

synonyms: belly button, bellybutton, omphalos, omphalus, umbilicus.

Roget 222: centrality, centricalness^†, center; middle etc. 68; focus etc. 74.    core, kernel; nucleus, nucleolus; heart, pole axis, bull's eye; nave, navel; umbilicus, backbone, marrow, pith; vertebra, vertebral column; hotbed; concentration etc. (convergence) 290; centralization; symmetry.    center of gravity, center of pressure, center of percussion, center of oscillation, center of buoyancy &c.; metacenter^†.    ... show more

Roget 68: middle, midst, mediety^†, mean etc. 29; medium, middle term; center etc. 222, mid-course etc. 628; mezzo termine [It]; juste milieu [Fr.] etc. 628; halfway house, nave, navel, omphalos^†; nucleus, nucleolus.    equidistance^†, bisection, half distance; equator, diaphragm, midriff; intermediate etc. 228.    ... show more

Dutch: navel
Polish: pępek

The center point or middle of something:
— The Incas believed that Cuzco was the navel of the universe.

synonym: navel point.