omphalos

from WordNet (r) 3.0 (2006)

omphalos
    n 1: 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" [syn: {navel}, {umbilicus},
         {bellybutton}, {belly button}, {omphalos}, {omphalus}]

from The Collaborative International Dictionary of English v.0.48

Omphalos \Om"pha*los\, n. [L., fr. Gr. ?.] (Anat.)
   The navel.
   [1913 Webster]