Forms: α. 7 vmbilike, -icke, umbilick, umbelic(k, 7, 9 umbilic. β. 7 vmbilique, umbelique. [ad. L. umbilīc-us UMBILICUS, related to Gr. ὀμφαλος, and ultimately to NAVEL sb. Hence also F. ombilic, † umbilic (1556), It. um-, ombilico, ombellico, Sp. ombligo, Pg. umbigo. In sense 1 prob. stressed umbili·c.]
† 1. The center; the middle point or part. Obs.
α. 1607. Bp. J. King, Serm. 5 Nov., 23. For the perpetration of it they went down into the bowells of the earth, but for the inuention to the very vmbilicke, and centre of the earth. Ibid. (1608), Serm. 24 March, 19. The verie middle and vmbilicke of natures prefined time.
1638. Sir T. Herbert, Trav. (ed. 2), 113. Ormus is as it were the umbelick of the gulph. Ibid., 265. Hell is in the Umbelic or navell of the world.
β. 1612. Peacham, Gentl. Exerc., III. 143. It was round, and equall from the vmbelique or middle point, to euery side.
1615. Sir E. Hoby, Curry-combe, vi. 248. Not only in Wales and Scotland, but euen in the vmbilique of the Saxons Dominion.
1638. Sir T. Herbert, Trav. (ed. 2), 214. In the umbelique or mid-part of this spatious Court is a quadrangular Tanck or Pond.
2. Geom. (See quots. 1875–6.)
1843. MacCullagh, in Proc. R. Irish Acad. (1846), II. 458. The focal hyperbola of the ellipsoid and the focal ellipse of the hyperboloid of two sheets, are umbilicar focals, and pass through the unbilics of these surfaces.
1875. P. Frost, Solid Geom. (ed. 2), I. 166. The point-circles in which the variable circle terminates are called umbilics.
1876. Handbk. Sci. App. S. Kens., 46. At special points, called umbilics, the greatest and least curvatures (and therefore all the curvatures) are equal to one another. The sphere has the peculiarity that every point on it is an umbilic.
