Definition of "umbilicus" in 英语

noun

1. (anatomy) navel

2. (loosely, sometimes proscribed) Umbilical cord

3. (botany) hilum

4. (zoology) A depression or opening in the center of the base of many spiral shells.

5. (zoology) Either of the two apertures in the calamus of a feather.

6. (space science) A tube connecting an astronaut or spacecraft to the mothership, through which supplies and samples can be transferred.

   • How about a 270 mile tether to an orbiting satellite? Oh, you'd like that, wouldn't you? Frank! Prepare to receive the umbilicus!

7. (geometry, obsolete) One of the foci of an ellipse or other curve.

8. (geometry) 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. (historical) An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled.