zydeco (n.)youdaoicibaDictYouDict[zydeco 词源字典]
1949, perhaps from Creole French pronunciation of French les haricots "the beans," part of the title of a popular dance tune ("les haricots sont pas salés").[zydeco etymology, zydeco origin, 英语词源]
zygoma (n.)youdaoicibaDictYouDict
"bony arch of the cheek," plural zygomata, 1680s, Modern Latin, from Greek zygoma, from zygon "yoke" (see jugular). So called because it connects the bones of the face with those of the skull about the ear.
zygomatic (adj.)youdaoicibaDictYouDict
"pertaining to the zygoma," 1709, from Latin zygomaticus, from Greek zygoma (see zygoma).
zygote (n.)youdaoicibaDictYouDict
1880, coined 1878 by German cytologist Eduard Strasburger (1844-1912), the widespread attribution to William Bateson being apparently erroneous; from Greek zygotos "yoked," from zygon "yoke" (see jugular).
Zyklon (n.)youdaoicibaDictYouDict
type of fumigant used to kill rats in enclosed spaces, such as holds of ships, boxcars, etc., 1926, from German Zyklon, commercial name of a type of hydrogen cyanide, said to be of unknown etymology, but it is the usual German form of the word cyclone. There were at least three varieties, A, B, and C, Zyklon-B being the one notoriously used in the Nazi death camps.
zymurgy (n.)youdaoicibaDictYouDict
branch of chemistry which deals with wine-making and brewing, 1868, from Greek zymo-, comb. form of zyme "a leaven" (from PIE root *yeue-; see juice) + -ourgia "a working," from ergon "work" (see organ).

The last word in many standard English dictionaries (and this one); but Century Dictionary ends with Zyxomma ("A genus of Indian dragon-flies") and in the OED [2nd ed.] the last word is zyxt, an obsolete Kentish form of the second person singular of see (v.).
At the dictionary's letter A
Mr. Brandt is young and gay
But when at last he reaches zed
He's in his wheelchair, nearly dead

[Einar Haugen]
ZimmeryoudaoicibaDictYouDict
"A kind of walking frame", 1950s: from Zimmer Orthopaedic Limited, the name of the manufacturer.
zona pellucidayoudaoicibaDictYouDict
"The thick transparent membrane surrounding a mammalian ovum before implantation", Mid 19th century: from Latin, literally 'pellucid girdle'.
zorbingyoudaoicibaDictYouDict
"A sport in which one is secured inside a large transparent ball which is then rolled along the ground or down hills", 1990s: invented word from zorb (the name of the ball used in this activity) + -ing1.
zoophyteyoudaoicibaDictYouDict
"A plant-like animal, especially a coral, sea anemone, sponge, or sea lily", Early 17th century: from Greek zōiophuton (see zoo-, -phyte).
zootoxinyoudaoicibaDictYouDict
"Any toxin derived from an animal", Early 20th cent..
zigzagyoudaoicibaDictYouDict
"A line or course having abrupt alternate right and left turns", Early 18th century: from French, from German Zickzack, symbolic of alternation of direction, first applied to fortifications.
zootomyyoudaoicibaDictYouDict
"The dissection or anatomy of animals", Mid 17th century: from modern Latin zootomia, probably influenced by late Latin anatomia (see anatomy).
ZoanthariayoudaoicibaDictYouDict
"A group of coelenterates with polyps that bear more than eight tentacles, including the sea anemones and stony corals", Modern Latin (plural), from Greek zōion 'animal' + anthos 'flower'.
zepto-youdaoicibaDictYouDict
"(Used in units of measurement) denoting a factor of 10−21", Adapted from septi-, on the pattern of combining forms such as peta- and exa-.
zooidyoudaoicibaDictYouDict
"An animal arising from another by budding or division, especially each of the individuals which make up a colonial organism and typically have different forms and functions", Mid 19th century: from zoo- 'relating to animals' + -oid.
zip codeyoudaoicibaDictYouDict
"A postal code consisting of five or nine digits", 1960s: Zip, acronym from zone improvement plan.
zero houryoudaoicibaDictYouDict
"The time at which a planned operation, typically a military one, is set to begin", First World War: from zero + hour.