<B>Zorn's lemma,</B><DL COMPACT><DD> (Mathematics.) the principle that if a set is partially ordered and each completely ordered subset has an upper bound, then the set has at least one element greater than any other element in the set. </DL>
<A NAME="zoroastrian">
<B>Zoroastrian, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> of or having to do with Zoroaster, a Persian religious teacher who lived about 600 B.C., or the religion founded by him. <DD><I>noun </I> a person believing in the teachings of Zoroaster, now represented by the Ghebers and the Parsis. Also, <B>Zarathustrian.</B> </DL>
<A NAME="zoroastrianism">
<B>Zoroastrianism, </B>noun.<DL COMPACT><DD> the religion founded by Zoroaster and practiced in Persia until the Moslem conquest in the 600's. Zoroastrianism taught that there is an eternal struggle between the powers of light and the powers of darkness, or good and evil. </DL>
<B>zoster, </B>noun.<DL COMPACT><DD><B> 1. </B><B>=shingles.</B> <DD><B> 2. </B>a belt or girdle worn in ancient Greece, especially by men. </DL>
<A NAME="zouave">
<B>Zouave, </B>noun.<DL COMPACT><DD><B> 1. </B>a member of any one of certain former light infantry regiments in the French army, noted for their bravery and dash and brilliant Oriental uniforms, and originally recruited from Algerian tribes. <DD><B> 2. </B>a soldier of any unit patterned on these in style of uniform, especially a member of certain volunteer regiments in the Union Army during the Civil War. </DL>
<A NAME="zouavejacket">
<B>Zouave jacket,</B><DL COMPACT><DD> a short jacket ending at or above the waist and open in front. </DL>
<A NAME="zouk">
<B>zouk, </B>noun.<DL COMPACT><DD> a lively form of Caribbean music with a strong beat, which originated in Guadeloupe and Martinique and combines elements of highlife, soca, salsa, funk, and disco music, played with a synthesizer and other electronic instruments. <BR> <I>Ex. What's missing from zouk is much verbal content ... But zouk, like Nigerian juju and the best reggae, tells a story through music itself (New York Times).</I> </DL>
<A NAME="zounds">
<B>zounds, </B>interjection.<DL COMPACT><DD> (Archaic.) a mild oath expressing surprise, anger, or disappointment. </DL>
<A NAME="zowie">
<B>zowie, </B>interjection.<DL COMPACT><DD> an exclamation as of wonder, surprise, or delight. </DL>
<A NAME="zoysia">
<B>zoysia, </B>noun.<DL COMPACT><DD> a type of hardy lawn grass, for use in warm, dry climates. <BR> <I>Ex. Zoysias ... have tolerance to the hottest weather (New York Times).</I> </DL>
<A NAME="zparticle">
<B>Z particle,</B><DL COMPACT><DD> an elementary particle with a neutral charge and a mass about 99 times that of the proton, held to be a carrier, or quantum unit, of the weak interaction. </DL>
<A NAME="zpg">
<B>ZPG</B> (no periods),<DL COMPACT><DD> zero population growth. </DL>
<A NAME="zr">
<B>Zr</B> (no period),<DL COMPACT><DD> zirconium (chemical element). </DL>
<A NAME="zubrowka">
<B>zubrowka, </B>noun.<DL COMPACT><DD> a yellow-colored vodka flavored with a sweet grass or herb. </DL>
<A NAME="zucchetto">
<B>zucchetto, </B>noun, pl. <B>-tos,</B> (Italian) <B>-ti.</B><DL COMPACT><DD> a small, round skullcap worn by Roman Catholic ecclesiastics. A priest wears black, a bishop violet, a cardinal red, and a pope white. </DL>
<A NAME="zucchini">
<B>zucchini, </B>noun, pl. <B>-ni</B> or <B>-nis.</B><DL COMPACT><DD><B> 1. </B>a kind of dark-green summer squash shaped like a cucumber and sometimes striped or flecked with light green, turning yellow when mature. It is eaten as a vegetable while still green. <DD><B> 2. </B>the plant it grows on. </DL>
<A NAME="zugzwang">
<B>Zugzwang, </B>noun.<DL COMPACT><DD> (Chess.) a situation in which a player is compelled to move against his will. </DL>
<A NAME="zulhijjah">
<B>Zulhijjah, </B>noun.<DL COMPACT><DD> the twelfth and last month of the Moslem year, during which the pilgrimage to Mecca must be made. It has 29 days, except during leap years, when it has 30 days. </DL>
<A NAME="zulkadah">
<B>Zulkadah, </B>noun.<DL COMPACT><DD> the eleventh month of the Moslem year. It has 30 days. </DL>
<A NAME="zulu">
<B>Zulu</B> (1), noun, pl. <B>-lus</B> or <B>-lu,</B> adjective.<DL COMPACT><DD><I>noun </I> <B>1. </B>a member of a large, (formerly) warlike, Bantu people of southeastern Africa chiefly in Natal, and resembling the Kaffirs. <DD><B> 2. </B>their language. <DD><I>adj. </I> of this people or their language. </DL>
<A NAME="zulu">
<B>Zulu</B> (2), noun.<DL COMPACT><DD> (U.S.) a code name for the letter <I>z,</I> used in transmitting radio messages. </DL>
<A NAME="zumpango">
<B>Zumpango, </B>noun. <B>=Cipango.</B></DL>
<A NAME="zuni">
<B>Zuni, </B>noun, pl. <B>-nis</B> or <B>-ni,</B> adjective.<DL COMPACT><DD><I>noun </I> <B>1. </B>a member of a tribe of Pueblo Indians living in western New Mexico. <DD><B> 2. </B>their language. <DD><I>adj. </I> of or having to do with this tribe or language. </DL>
<B>Zwicky galaxy,</B><DL COMPACT><DD> any one of a class of galaxies that recede at about the same speed, have relatively small masses, and concentrate most of their luminosity in a small area. </DL>
<A NAME="zwieback">
<B>zwieback, </B>noun.<DL COMPACT><DD> a kind of bread or cake which, after baking, is cut into slices and toasted brown and crisp in an oven. </DL>
<A NAME="zwinglian">
<B>Zwinglian, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I>of or having to do with Ulrich Zwingli (1484-1531), a Swiss Protestant reformer, or his doctrines. <DD><I>noun </I> a follower of Ulrich Zwingli. </DL>
<A NAME="zwinglianism">
<B>Zwinglianism, </B>noun.<DL COMPACT><DD> the doctrinal system of Ulrich Zwingli, Lutheran in essence but differing principally in denying the real presence of Christ in the Eucharist, which he maintained was a commemoration of the sacrifice of Christ rather than a renewal of it. </DL>
<B>zwitterion, </B>noun.<DL COMPACT><DD> (Physics.) an ion which has both a positive and a negative charge, on opposite sides, as in certain protein molecules. </DL>
<A NAME="zwitterionic">
<B>zwitterionic, </B>adjective.<DL COMPACT><DD> of or having to do with a zwitterion. </DL>
<A NAME="zydeco">
<B>zydeco</B> or <B>Zydeco, </B>noun, pl. <B>-cos.</B><DL COMPACT><DD> (U.S.) a style of country music similar to bluegrass but with elements of rock, blues, and Latin-American music. </DL>
<A NAME="zyg">
<B>zyg-,</B><DL COMPACT><DD> (combining form.) the form of <B>zygo-</B> before vowels, as in <BR> <I>Ex. zygapophysis.</I> </DL>
<A NAME="zygapophyseal">
<B>zygapophyseal</B> or <B>zygapophysial, </B>adjective.<DL COMPACT><DD> of or having to do with a zygapophysis; articular, as a vertebral process. </DL>
<A NAME="zygapophysis">
<B>zygapophysis, </B>noun, pl. <B>-ses.</B><DL COMPACT><DD> (Anatomy.) one of the lateral processes upon the neural arch of a vertebra which interlock each vertebra with the one above and below. Each vertebra normally has four, two anterior and two posterior. </DL>
<A NAME="zygo">
<B>zygo-,</B><DL COMPACT><DD> (combining form.) <DD><B> 1. </B>yoke; yoked or paired. <BR> <I>Ex. Zygodactyl = having the toes in pairs.</I> <DD><B> 2. </B>reproduction by zygosis, as in <BR> <I>Ex. zygospore.</I> <DD> Also, <B>zyg-</B> before vowels. </DL>
<A NAME="zygodactyl">
<B>zygodactyl, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> having the toes arranged in pairs, with two before and two behind, as the feet of a climbing bird, or the bird itself. <DD><I>noun </I> a zygodactyl bird, such as a parrot. </DL>
<B>zygoma, </B>noun, pl. <B>-mata.</B><DL COMPACT><DD><B> 1. </B>the bony arch below the socket of the eye in vertebrates, formed by the zygomatic bone (cheekbone) and the zygomatic process of the temporal bone; zygomatic arch. <DD><B> 2. </B><B>=zygomatic process.</B> <DD><B> 3. </B><B>=zygomatic bone.</B> </DL>
<A NAME="zygomatic">
<B>zygomatic, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> <B>1. </B>of or having to do with the zygoma. <BR> <I>Ex. zygomatic muscle.</I> <DD><B> 2. </B>constituting the zygoma. <DD><I>noun </I> <B>=zygomatic bone.</B> </DL>
<A NAME="zygomaticarch">
<B>zygomatic arch,</B> <B>=zygoma.</B></DL>
<A NAME="zygomaticbone">
<B>zygomatic bone,</B><DL COMPACT><DD> the three-sided bone forming the lower boundary of the socket of the eye; cheekbone; malar bone; jugal bone; zygoma. </DL>
<A NAME="zygomaticprocess">
<B>zygomatic process,</B><DL COMPACT><DD> a process of the temporal bone which articulates with the zygomatic bone to form the zygoma. </DL>
<A NAME="zygomorphic">
<B>zygomorphic, </B>adjective.<DL COMPACT><DD> (Botany.) (of a flower) divisible vertically into similar halves in only one way, as the sweet pea. </DL>
<A NAME="zygomorphism">
<B>zygomorphism, </B>noun.<DL COMPACT><DD> the character of being zygomorphic. </DL>
<B>zygophyllaceous, </B>adjective.<DL COMPACT><DD> belonging to a family of dicotyledonous herbs, shrubs, and trees typified by the bean caper, and including the creosote bush and lignum vitae. </DL>
<A NAME="zygophyte">
<B>zygophyte, </B>noun.<DL COMPACT><DD> (Botany.) a plant in which reproduction consists of the fusion of two similar gametes (zygospores). </DL>
<B>zygospore, </B>noun.<DL COMPACT><DD> (Botany.) a spore formed by the union of two similar gametes, as in various algae. </DL>
<A NAME="zygosporic">
<B>zygosporic, </B>adjective.<DL COMPACT><DD> of or having to do with a zygospore. </DL>
<A NAME="zygote">
<B>zygote, </B>noun.<DL COMPACT><DD><B> 1. </B>the cell formed by the union of two germ cells or gametes. A fertilized egg is a zygote. <DD><B> 2. </B>the individual which develops from this cell. </DL>
<A NAME="zygotene">
<B>zygotene, </B>noun.<DL COMPACT><DD> stage of prophase of meiosis in which homologous chromosomes become paired. </DL>
<A NAME="zygotic">
<B>zygotic, </B>adjective.<DL COMPACT><DD><B> 1. </B>of a zygote or zygosis. <DD><B> 2. </B>like a zygote or zygosis. </DL>
<A NAME="zym">
<B>zym-,</B><DL COMPACT><DD> (combining form.) the form of <B>zymo-</B> before vowels, as in <BR> <I>Ex. zymoid.</I> </DL>
