Umbilicus Um`bi*li"cus, n. [L. See {Umbilic}.] 1. (Anat.) 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. [1913 Webster]

2. (Gr. & Rom. Antiq.) An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled. --Dr. W. Smith. [1913 Webster]

3. (Bot.) The hilum. [1913 Webster]

4. (Zo["o]l.) (a) A depression or opening in the center of the base of many spiral shells. (b) Either one of the two apertures in the calamus of a feather. [1913 Webster]

5. (Geom.) (a) One of foci of an ellipse, or other curve. [Obs.] (b) 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}. [1913 Webster]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Umbilic — Um*bil ic, n. [From L. umbilicus: cf. F. ombilic. See {Navel}.] 1. The navel; the center. [Obs.] The umbilic of the world. Sir T. Herbert. [1913 Webster] 2. (Geom.) An umbilicus. See {Umbilicus}, 5 (b) . [1913 Webster] …   The Collaborative International Dictionary of English

  • Umbilic — Um*bil ic, a. (Anat.) See {Umbilical}, 1. [1913 Webster] …   The Collaborative International Dictionary of English

  • umbilic — adjective Of, pertaining to, or having a navel or umbilicus …   Wiktionary

  • umbilic — «us (L). The navel …   Dictionary of word roots and combining forms

  • umbilic — noun ( s) Etymology: Latin umbilicus navel, middle, center obsolete : a middle point : center …   Useful english dictionary

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  • Catastrophe theory — This article refers to the study of dynamical systems. For other meanings, see catastrophe. In mathematics, catastrophe theory is a branch of bifurcation theory in the study of dynamical systems; it is also a particular special case of more… …   Wikipedia

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  • Umbilical point — In the differential geometry of surfaces in three dimensions, umbilics or umbilical points are points which are locally spherical. At such points both principal curvatures are equal, and every tangent vector is a principal direction . Umbilic… …   Wikipedia

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