clay

Etymology

From Middle English cley, clay, from Old English clǣġ (“clay”), from Proto-West Germanic *klaij, from Proto-Germanic *klajjaz (“clay”), from Proto-Indo-European *gley- (“to glue, paste, stick together”). Cognate with Dutch klei (“clay”), Low German Klei (“clay”), German Klei, Danish klæg (“clay”); compare Ancient Greek γλία (glía), Latin glūten (“glue”) (whence ultimately English glue), Russian глина (glina, “clay”). Related also to clag, clog.

noun

1. A mineral substance made up of small crystals of silica and alumina, that is ductile when moist; the material of pre-fired ceramics.
2. An earth material with ductile qualities.
3. (tennis) A tennis court surface made of crushed stone, brick, shale, or other unbound mineral aggregate.
   The French Open is played on clay.
4. (biblical) The material of the human body.
5. (geology) A particle less than 3.9 microns in diameter, following the Wentworth scale.
6. A clay pipe for smoking tobacco.
7. (firearms, informal) A clay pigeon.
   We went shooting clays at the weekend.
8. (informal) Land or territory of a country or other political region, especially when subject to territorial claims
   Danzig is rightfully German clay.
9. A moth, Mythimna ferrago

verb

1. (transitive) To add clay to, to spread clay onto.
2. (transitive, of sugar) To purify using clay.
   1776, Adam Smith, An Inquiry into the Nature and Causes of the Wealth of Nations, Book IV, Chapter 7: Of Colonies, Part 2: Causes of Prosperity of New Colonies, They amounted, therefore, to a prohibition, at first of claying or refining sugar for any foreign market, and at present of claying or refining it for the market, which takes off, perhaps, more than nine-tenths of the whole produce.
   1809, Jonathan Williams, “On the Process of Claying Sugar”, in Transactions of the American Philosophical Society, volume 6:
   The Portuguese had mastered the technique of claying sugar, and other European nations tried to learn the secrets from them. 1985, Stuart B. Schwartz, Sugar Plantations in the Formation of Brazilian Society: Bahia, 1550-1835, page 200