With the youngsters on Fridays we do 'Alphabets' at the beginning (ie Boys names, etc). When we come to 'Y' I always say 'Why do we do this?' and when we come to 'X' we usually try and get X-ray or Xylophone in somehow. According to Johnson there are no English words beginning with 'X' although even in his time there were some he could have included. Alphabet books for children frequently feature the word xylophone because it is one of the few words beginning with x that a child (or most adults, for that matter) would know. The majority of English words beginning with x, including many obscure scientific terms, are of Greek origin, the x, pronounced (z), representing the Greek letter xi. In the case of xylophone, xylo- is a form meaning "wood," derived from Greek xulon, "wood," and -phone represents Greek phone, "voice, sound," the same element found in words such as telephone, microphone and megaphone. Xylophone is first recorded in the April 7, 1866, edition of the Athenaeum: "A prodigy ... who does wonderful things with little drumsticks on a machine of wooden keys, called the 'xylophone.'"
Here is a random list of 10 'X' words.
1. Xanthum gum - A natural gum of high molecular weight produced by culture fermentation of glucose and used as a stabilizer in commercial food preparation. Named for its yellow colour.
2. Xenogam - Cross pollination (not marrying a foreigner)
3. Xerography - A dry photographic or photocopying process in which a negative image formed by a resinous powder on an electrically charged plate is electrically transferred to and thermally fixed as positive on a paper or other copying surface.
4. Xiphoid - A. Shaped like a sword. B. Of or relating to the xiphisternum (part of the sternum).
5. X-ray star - A celestial object, especially a star, that emits a major portion of its radiation in x-rays.
6. Xylene - A. Any of three flammable isomeric hydrocarbons, C6H4(CH3)2, obtained from wood and coal tar. B. A mixture of xylene isomers used as a solvent in making lacquers and rubber cement and as an aviation fuel.
7. Xylitol - A sweet white crystalline alcohol, C5H12O5, derived from xylose and used especially as a sugar substitute in oral health products.
8. Xylophagous - A. Feeding on wood, as certain insects or insect larvae. B. Destructive to wood, as certain crustaceans or fungi.
9. Xylophone - See above.
10. XYZ - Informal Used to indicate to someone that the zipper of his or her trousers/pants is open. (eXamine Your Zipper). The joke here is also that the XYZ company make zippers.