Zen (n.)youdaoicibaDictYouDict[Zen 词源字典]
school of Mahayana Buddhism, 1727, from Japanese, from Chinese ch'an, ultimately from Sanskrit dhyana "thought, meditation," from PIE root *dheie- "to see, look" (cognates: Greek sema "sign, mark, token"). As an adjective from 1881.[Zen etymology, Zen origin, 英语词源]
Zend (n.)youdaoicibaDictYouDict
1715, "Parsee sacred book" (in full, Zend-Avesta, 1620s), from Old Persian zend, from Pahlavi zand "commentary." First used 1771 in reference to the language of the Zend-Avesta by French scholar Abraham Hyacinthe Anquetil-Duperron (1731-1805).
zenith (n.)youdaoicibaDictYouDict
"point of the heavens directly overhead at any place," late 14c., from Old French cenith (Modern French zénith), from Medieval Latin cenit, senit, bungled scribal transliterations of Arabic samt "road, path," abbreviation of samt ar-ras, literally "the way over the head." Letter -m- misread as -ni-.

The Medieval Latin word could as well be influenced by the rough agreement of the Arabic term with classical Latin semita "sidetrack, side path" (notion of "thing going off to the side"), from se- "apart" + *mi-ta-, suffixed zero-grade form of PIE root *mei- (1) "to change" (see mutable). Figurative sense of "highest point or state" is from c. 1600.
late 20c. word-forming element used in reference to the planet Jupiter, from Greek zeno-, comb. form from Zeus (see Zeus; also compare Zenobia).
fem. proper name, from Greek Zenobia, literally "the force of Zeus," from Zen, collateral form of Zeus, + bia "strength, force," cognate with Sanskrit jya "force, power" (see Jain).
Zenonian (adj.)youdaoicibaDictYouDict
1843, pertaining to one of two Greek thinkers: Zeno of Elea ("Zeno of the Paradoxes," 5c. B.C.E.), who disproved the possibility of motion; and Zeno of Citium (c. 300 B.C.E.), founder of stoicism.
zep (n.)youdaoicibaDictYouDict
abbreviation of zeppelin, attested by 1915.
masc. proper name, Biblical ninth of the prophets, from Hebrew Tzephanyah "the Lord has hidden."
zephyr (n.)youdaoicibaDictYouDict
mid-14c., from Old English Zefferus, from Latin Zephyrus (source also of French zéphire, Spanish zefiro, Italian zeffiro), from Greek Zephyros "the west wind" (sometimes personified as a god), probably related to zophos "the west, the dark region, darkness, gloom." Extended sense of "mild breeze" is c. 1600. Related: Zephyrean.
zeppelin (n.)youdaoicibaDictYouDict
1900, from German Zeppelin, short for Zeppelinschiff "Zeppelin ship," after Count Ferdinand von Zeppelin (1838-1917), German general who perfected its design. Compare blimp. Related: Zeppelinous.
zero (n.)youdaoicibaDictYouDict
"figure which stands for naught in the Arabic notation," also "the absence of all quantity considered as quantity," c. 1600, from French zéro or directly from Italian zero, from Medieval Latin zephirum, from Arabic sifr "cipher," translation of Sanskrit sunya-m "empty place, desert, naught" (see cipher (n.)).

A brief history of the invention of "zero" can be found here. Meaning "worthless person" is recorded from 1813. As an adjective from 1810. Zero tolerance first recorded 1972, originally U.S. political language. Zero-sum in game theory is from 1944 (von Neumann), indicating that if one player wins X amount the other or others must lose X amount.
zero (v.)youdaoicibaDictYouDict
in zero in, 1944, from zero (n.); the image is from instrument adjustment to a setting of "zero" (1909 in this sense, originally in rifle-shooting). Related: Zeroed; zeroing.
zest (n.)youdaoicibaDictYouDict
1670s, from French zeste "piece of orange or lemon peel used as a flavoring," of unknown origin. Sense of "thing that adds flavor" is 1709; that of "keen enjoyment" first attested 1791.
zestful (adj.)youdaoicibaDictYouDict
1797, from zest + -ful. Related: Zestfully; zestfulness.
zesty (adj.)youdaoicibaDictYouDict
1789, from zest + -y (2). Related: Zestily; zestiness.
zeta (n.)youdaoicibaDictYouDict
sixth letter of the Greek alphabet; see zed.
zetetic (adj.)youdaoicibaDictYouDict
"proceeding by inquiry," 1640s, from Modern Latin zeteticus, from Greek zetetikos "searching, inquiring," from zetetos, verbal adjective of zetein "seek for, inquire into." Related: Zetetical.
zeugma (n.)youdaoicibaDictYouDict
1580s, "a single word (usually a verb or adjective) made to refer to two or more nouns in a sentence" (but properly applying to only one of them), from Greek zeugma, "a zeugma; that which is used for joining; boat bridge," literally "a yoking," from zeugnynai "to yoke" (see jugular).
supreme god of the ancient Greeks and master of the others, 1706, from Greek, from PIE *dewos- "god" (cognates: Latin deus "god," Old Persian daiva- "demon, evil god," Old Church Slavonic deivai, Sanskrit deva-), from root *dyeu- "to gleam, to shine;" also the root of words for "sky" and "day" (see diurnal). The god-sense is originally "shining," but "whether as originally sun-god or as lightener" is not now clear.
in reference to showgirls or stage revues, 1913, from Florenz Ziegfeld (1869-1932), U.S. theatrical producer, who staged annual "follies" from 1907-1931.