<B>ultraviolet rays,</B><DL COMPACT><DD> the invisible rays in the part of the spectrum beyond the violet. They are present in sunlight and light from sun lamps, and are used for healing, forming vitamins, and as sterilizers and disinfectants. Ultraviolet rays are more refrangible than violet rays as diffracted by a grating. </DL>
<A NAME="ultravires">
<B>ultra vires,</B><DL COMPACT><DD> going beyond the powers granted by authority or by law. <BR> <I>Ex. His Lordship made a declaration in this action that the expulsion of the plaintiff ... was invalid and ultra vires (London Times).</I> </DL>
<A NAME="ultravirus">
<B>ultravirus, </B>noun.<DL COMPACT><DD> a virus which can go through the finest bacterial filters. </DL>
<A NAME="ulu">
<B>ulu, </B>noun.<DL COMPACT><DD> a type of knife used by the Eskimos, made of metal or chipped stone, with a flat curved blade, especially for cutting blubber. <BR> <I>Ex. The ulu remains the ideal instrument for skinning seal (Harper's).</I> </DL>
<A NAME="ululant">
<B>ululant, </B>adjective. =howling.</DL>
<A NAME="ululate">
<B>ululate, </B>intransitive verb, <B>-lated,</B> <B>-lating.</B><DL COMPACT><DD><B> 1. </B>to howl, as a dog or wolf does. <DD><B> 2. </B>to lament loudly. </DL>
<A NAME="ululation">
<B>ululation, </B>noun.<DL COMPACT><DD><B> 1. </B>a howl or wail. <DD><B> 2. </B>the act of howling or wailing. </DL>
<A NAME="ulyssean">
<B>Ulyssean, </B>adjective.<DL COMPACT><DD><B> 1. </B>of or having to do with Ulysses. <DD><B> 2. </B>resembling Ulysses, as in craft or deceit, or in extensive wanderings. <DD><B> 3. </B>characteristic of Ulysses. </DL>
<A NAME="ulysses">
<B>Ulysses, </B>noun.<DL COMPACT><DD><B> 1. </B>(Greek Legend.) a king of Ithaca and hero of the Trojan War, known for his wisdom and shrewdness. Ulysses, who was called Odysseus by the Greeks, is the hero of Homer's <I>Odyssey,</I> which tells about his adventures. <DD><B> 2. </B>a novel by James Joyce, published in 1922. </DL>
<A NAME="um">
<B>um, </B>interjection.<DL COMPACT><DD> a low sound used especially to express hesitation and doubt. </DL>
<A NAME="umayyad">
<B>Umayyad, </B>noun, pl. <B>-yads,</B> <B>-yades.</B> =Omayyad.</DL>
<A NAME="umbel">
<B>umbel, </B>noun.<DL COMPACT><DD> a flower cluster in which stalks nearly equal in length spring from a common center, as in parsley. Their summits form a level or slightly curved surface. A simple umbel has only one set of rays, as in the ginseng; in a compound umbel the pedicels or rays each bear an umbel of flowers, as in the carrot and dill. </DL>
<A NAME="umbellar">
<B>umbellar, </B>adjective. =umbellate.</DL>
<A NAME="umbellate">
<B>umbellate, </B>adjective.<DL COMPACT><DD> (Botany.) <DD><B> 1. </B>of or like an umbel. <DD><B> 2. </B>having umbels; forming an umbel or umbels. adv. <B>umbellately.</B> </DL>
<A NAME="umbellated">
<B>umbellated, </B>adjective. =umbellate.</DL>
<A NAME="umbellet">
<B>umbellet, </B>noun. =umbellule.</DL>
<A NAME="umbellifer">
<B>umbellifer, </B>noun.<DL COMPACT><DD> any plant of the parsley family. </DL>
<A NAME="umbelliferous">
<B>umbelliferous, </B>adjective.<DL COMPACT><DD> (Botany.) <DD><B> 1. </B>bearing an umbel or umbels. <BR> <I>Ex. The parsley and carrot are umbelliferous.</I> <DD><B> 2. </B>belonging to the parsley family. </DL>
<A NAME="umbellulate">
<B>umbellulate, </B>adjective.<DL COMPACT><DD> (Botany.) having or arranged in umbellules. </DL>
<A NAME="umbellule">
<B>umbellule, </B>noun.<DL COMPACT><DD> (Botany.) a small or partial umbel; an umbel formed at the end of one of the primary pedicels or rays of a compound umbel. </DL>
<A NAME="umber">
<B>umber</B> (1), noun, adjective, verb.<DL COMPACT><DD><I>noun </I> <B>1. </B>a heavy, brown earth that is any one of various mixtures of clay and iron oxide, principally of alumina, iron oxide, and magnesium oxide. In its natural state it is used as a brown pigment called raw umber. After heating it becomes reddish brown and is called burnt umber. <DD><B> 2. </B>a brown or reddish brown, like either of these pigments. <DD><I>adj. </I> brown or reddish-brown. <DD><I>v.t. </I> to stain or paint with umber; make of a brown color. </DL>
<B>umbery, </B>adjective.<DL COMPACT><DD><B> 1. </B>of or having to do with umber. <DD><B> 2. </B>of the color of umber; dark brown. </DL>
<A NAME="umbilic">
<B>umbilic, </B>noun.<DL COMPACT><DD> a point on a surface where the radii of curvature are all equal and a sphere osculates the surface. </DL>
<A NAME="umbilical">
<B>umbilical, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> <B>1. </B>of or having to do with the navel or umbilical cord. <DD><B> 2. </B>situated near the navel or the umbilical cord. <DD><B> 3. </B>formed, placed, or shaped like a navel or umbilical cord. <BR> <I>Ex. The Chapter-house is large, supported as to its arched roof by one umbilical pillar (Daniel Defoe).</I> <DD><I>noun </I> <B>=umbilical cord.</B> </DL>
<A NAME="umbilicalcord">
<B>umbilical cord,</B><DL COMPACT><DD><B> 1. </B>a cordlike structure that connects the navel of an embryo or fetus with the placenta of the mother. It carries nourishment to the fetus and carries away waste. <DD><B> 2. </B>(Figurative.) something that binds or unites closely; strong bond or tie. <BR> <I>Ex. He could never break the umbilical cord which held him to nature (Emerson).</I> <DD><B> 3. </B>an electric cable, fuel line, or the like, connected to a missile on its launching site and released just before launching. <DD><B> 4. </B>any long cord or cable by which a person or thing remains connected to aspacecraft, ship, the ground, or other surface. </DL>
<A NAME="umbilicalhernia">
<B>umbilical hernia,</B><DL COMPACT><DD> hernia of the intestine at the navel; exomphalos. </DL>
<A NAME="umbilicate">
<B>umbilicate, </B>adjective.<DL COMPACT><DD><B> 1. </B>navel-shaped. <DD><B> 2. </B>having an umbilicus or navel. </DL>
<A NAME="umbilicated">
<B>umbilicated, </B>adjective. =umbilicate.</DL>
<A NAME="umbilication">
<B>umbilication, </B>noun.<DL COMPACT><DD><B> 1. </B>a central depression resembling a navel. <DD><B> 2. </B>the condition of being umbilicate. </DL>
<A NAME="umbilicus">
<B>umbilicus, </B>noun, pl. <B>-ci.</B><DL COMPACT><DD><B> 1. </B>(Anatomy.) the navel; depression or scar on the middle of the abdomen, marking the spot where the umbilical cord was attached. <DD><B> 2. </B>(Biology.) a small depression or hollow suggestive of a navel, such as the hilum of a seed. </DL>
<A NAME="umbiliform">
<B>umbiliform, </B>adjective.<DL COMPACT><DD> like a navel. </DL>
<A NAME="umblepie">
<B>umble pie,</B><DL COMPACT><DD> (Obsolete.) a pie made from umbles; humble pie. <BR> <I>Ex. Mrs. Turner ... did bring us an umble pie hot out of her oven (Samuel Pepys).</I> </DL>
<A NAME="umbles">
<B>umbles, </B>noun pl.<DL COMPACT><DD> (Obsolete.) the heart, liver, lungs, and other edible internal parts of an animal, especially of a deer; numbles. </DL>
<A NAME="umbo">
<B>umbo, </B>noun, pl. <B>umbones,</B> <B>umbos.</B><DL COMPACT><DD><B> 1. </B>a projection or knob, often pointed, near or at the center of a shield. <DD><B> 2. </B>any elevation resembling this, as in the eardrum. <DD><B> 3. </B>(Zoology.) the oldest and most protuberant portion of a bivalve mollusk shell, located near the hinge. </DL>
<A NAME="umbonal">
<B>umbonal, </B>adjective. =protuberant.</DL>
<A NAME="umbonate">
<B>umbonate, </B>adjective.<DL COMPACT><DD><B> 1. </B>having an umbo or boss. <DD><B> 2. </B>like an umbo or boss. </DL>
<B>umbra, </B>noun, pl. <B>-brae,</B> <B>-bras.</B><DL COMPACT><DD><B> 1. </B>the completely dark shadow cast, as by the earth or moon, during an eclipse. <DD><B> 2. </B>the dark inner or central part of a sunspot. <DD><B> 3. </B>shade; shadow. </DL>
<A NAME="umbrage">
<B>umbrage, </B>noun.<DL COMPACT><DD><B> 1. </B>suspicion that one has been slighted or injured; feeling offended; resentment. <BR> <I>Ex. Unless my pacific disposition was displeasing, nothing else could have given umbrage (George Washington).</I> (SYN) offense, pique. <DD><B> 2. </B>the foliage of trees or vines, providing shade. <BR> <I>Ex. at the foot of some tree of friendly umbrage (Charlotte Bronte).</I> <DD><B> 3. </B>(Archaic.) a faint likeness; shadowy outline or indication. <DD><B> 4. </B>(Obsolete.) shade; shadow. <BR><I>expr. <B>take umbrage,</B> </I>to take offense; feel insulted or resentful. <BR> <I>Ex. He took umbrage at the criticism.</I> </DL>
<A NAME="umbrageous">
<B>umbrageous, </B>adjective.<DL COMPACT><DD><B> 1. </B>likely to take offense; easily insulted. <DD><B> 2. </B>revealing or displaying umbrage; offended; insulted. <DD><B> 3. </B>giving shade; shady. <DD><B> 4. </B>covered over or surrounded by that which cuts off light; somewhat dark; shaded. adv. <B>umbrageously.</B> noun <B>umbrageousness.</B> </DL>
<A NAME="umbral">
<B>umbral, </B>adjective.<DL COMPACT><DD> of or having to do with an umbra. <BR> <I>Ex. the umbral shadow of an eclipse.</I> </DL>
<A NAME="umbrella">
<B>umbrella, </B>noun, adjective.<DL COMPACT><DD><I>noun </I> <B>1. </B>a light, portable, folding frame covered with cloth or plastic, used as a protection against rain or sun. <DD><B> 2. </B>(Figurative:) <BR> <I>Ex. This is just short of the total 256 million bushels put under the Federal price umbrella for the entire season last year (Wall Street Journal).</I> <DD><B> 3. </B>the gelatinous disk- or bowl-shaped body of a jellyfish; bell. <DD><I>adj. </I> <B>1. </B>resembling an umbrella. <DD><B> 2. </B>(Figurative:) <BR> <I>Ex. Within this large umbrella framework it should be possible to work out the necessary system of nuclear control (Listener). Therapies based on conditioning and learning theory [are] grouped under the umbrella term "behaviour therapy" (New Scientist).</I> (SYN) general, comprehensive. adj. <B>umbrellalike.</B> </DL>
