carat

Pronunciation

• IPA: /ˈkæ.ɹət/ (UK); /ˈkɛɹ.ət/ (US)^[1]

Etymology

It is borrowed from Middle French carat,^[2][3][4][5] from Italian carato and Medieval Latin carratus,^[3][4][5][6] from Arabic قِيرَاط (qīrāṭ, “carob pod; weight of four grains”),^{[2][3][4][5][6]} from Ancient Greek κεράτιον (kerátion, “carob seed; a small weight”),^{[2][3][4][5][6]} literally “little horn”, a diminutive of kéras “horn”.^{[2][3][4][5][6]}

Earliest recorded meaning

A measure of the fineness of gold (1469 in Barnhart; late 15th century in Etymonline).^[3][4]

Semantic evolution

Carob seeds were a standard for weighing small quantities in the ancient world.^[4] The Greek weight was equal to the Roman siliqua, one twenty-fourth of a gold solidus of Constantine, so the carat came to express a proportion of one twenty-fourth, especially in stating the purity of gold: 18-carat gold is eighteen parts gold to six of alloy.^[4][7] As a unit of weight for diamonds and other gems it dates from 1555–75,^[3][5][7] and the metric carat is now 200 milligrams.^[2][5][6] In the United States the gold measure is usually spelled karat.^[4][5]

Timeline

• 1469 – a measure of the fineness of gold (Barnhart).^[3]
• 1555 – a unit of weight for gems (Barnhart, Merriam-Webster).^[3][5]
• 1575 – the weight of gems (OED).^[7]
• 1601 – the carob seed (obsolete).^[7]

Modern meaning

Noun

1. A unit of weight for precious stones and pearls, equal to 200 milligrams.
2. A variant spelling of karat, a measure of the purity of gold in twenty-fourths.

Related words

• karat
• carob
• horn
• keratin

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
3. ^ a b c d e f g h i Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
4. ^ a b c d e f g h i Harper, Douglas, Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e f g h i Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e Random House Webster's Unabridged Dictionary (1999), 2nd ed., New York: Random House
7. ^ a b c d Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press