- (n.) The hilum.
- (n.) A depression or opening in the center of the base of many spiral shells.
- (n.) The depression or mark, in the median line of the abdomen, which indicates the point where the umbilical cord separated from the fetus; the navel.
- (n.) Either one of the two apertures in the calamus of a feather.
- (n.) One of foci of an ellipse or other curve.
- (n.) 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. Called also umbilic.
- (n.) An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). umbilicus. Retrieved September 20, 2026, from http://smartdefine.org/umbilicus/definitions/2076119 |
| Chicago | Webster's. 2011. "umbilicus" http://smartdefine.org/umbilicus/definitions/2076119 (accessed September 20, 2026). |
| Harvard | Webster's 2011, umbilicus, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/umbilicus/definitions/2076119>. |
| MLA | Webster's. "umbilicus" 28 May 2011. Web. 20 September 2026. <http://smartdefine.org/umbilicus/definitions/2076119> |