umbilicus

noun

Etymology: Etymology tree Proto-Indo-European *h₃nóbʰōl Latin umbilīcusbor. English umbilicus Borrowed from Latin umbilīcus (“navel”).

1. A navel.
2. Umbilical cord

   “Although I have been tempted to cut the umbilicus, and pass a ligature round the remaining portion on one occasion, yet I now deem such interference officious and uncalled - for at this eventful period.”

   “She ate the umbilicus, and the afterbirth, which is supposed to be good for them. Then she licked off the first kitten and was ready for the next.”

3. A hilum.
4. A depression or opening in the center of the base of many spiral shells.
5. Either of the two apertures in the calamus of a feather.
6. A tube connecting an astronaut or spacecraft to the mothership, through which supplies and samples can be transferred.

   “The importance of the visual analyzer is further increased when the cosmonaut is in free space with only the slight support of an umbilicus.”

   “Penetrators will be connected by an umbilicus to an afterbody containing imaging and meteorological instruments.”

7. One of the foci of an ellipse or other curve.
8. A point of a surface at which the curvatures of the normal sections are all equal to each other.

   “A sphere may be osculatory to the surface in every direction at an umbilicus.”

9. An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled.

   “The ends of the umbilicus were called cornua (i.e. horns) in Latin, and were usually adorned with some pretty device”