Index of English words, starting with "um"

(1) - Umbilicus (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.
(2) - Umbilicus (n.) One of foci of an ellipse, or other curve.
(3) - Umbilicus (n.) Either one of the two apertures in the calamus of a feather.
(4) - Umbilicus (n.) A depression or opening in the center of the base of many spiral shells.
(5) - Umbilicus (n.) The hilum.
(6) - Umbilicus (n.) An ornamented or painted ball or boss fastened at each end of the stick on which manuscripts were rolled.
(7) - Umbilicus (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.

(1) - Umbles (n. pl.) The entrails and coarser parts of a deer; hence, sometimes, entrails, in general.

(1) - Umbo (n.) One of the lateral prominence just above the hinge of a bivalve shell.
(2) - Umbo (n.) A boss, or rounded elevation, or a corresponding depression, in a palate, disk, or membrane; as, the umbo in the integument of the larvae of echinoderms or in the tympanic membrane of the ear.
(3) - Umbo (n.) The boss of a shield, at or near the middle, and usually projecting, sometimes in a sharp spike.