navel

/ˈneɪvəl/
noun
  1. The small hollow or bump in the middle of the belly where the umbilical cord was attached at birth; a belly button.
    • He has a small scar near his navel from an old surgery.
    • The baby's navel healed quickly after the cord fell off.
    • She wore a crop top that showed her navel.
  2. A central point or part of something; the middle.
    • This plaza is the navel of the town, where all the main streets meet.
    • The ancient city was considered the navel of the empire.
    • In some cultures, a mountain is seen as the navel of the world.