chi

Chi, the Greek letter, and chi, vital energy in Chinese thought, are separate words.^[1][2]

chi¹ Greek letter

Pronunciation

• IPA: /kaɪ/^[3]

Etymology

The letter name is borrowed from Ancient Greek χῖ (khî), earlier χεῖ (kheî).^[1][4][5] It stood for a kh sound (see ch), and its X shape made the name a sign of things placed crosswise, as in χίασμα (khíasma, “two things placed crosswise”) (see chiasmus).^[6] Some Greek dialects used it for the ks sound of xi,^[6] and Latin took this over, so in alphabets derived from Latin its value is that of English X.^[6]

Earliest recorded meaning

The name of χ, the 22nd letter of the Greek alphabet: about 1400 in the OED, the 15th century in Merriam-Webster.^[7][1]

Semantic evolution

As a Greek numeral χ stood for 600, and in inscriptions for 1,000.^[4] The chi-square test of statistics, which measures goodness of fit, is named from the letter.^[8][9]

Timeline

• c. 1400 – the letter name.^[7]

Modern meaning

Noun

1. The 22nd letter of the Greek alphabet (Χ, χ), transliterated ch or kh.

chi² vital energy

Pronunciation

• IPA: /tʃiː/^[3]

Etymology

The vital energy is borrowed from Chinese 氣 (qì, “air, breath, spirit”),^[1][2][5] also written ch'i or qi.^[1][5]

Earliest recorded meaning

Vital energy: 1850.^[10]

Timeline

• 1850 – chi, vital energy.^[10]

Modern meaning

Noun

1. In Taoism and other Chinese thought, the vital force believed to animate the body and to be present in all things; it is central to acupuncture and to exercises such as tai chi.

Related words

• chiasmus
• chi-square
• qi

References

1. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
2. ^ a b Pearsall, Judy, ed. (1998), The New Oxford Dictionary of English, Oxford: Clarendon Press
3. ^ a b Jones, Daniel (2011), Cambridge English Pronouncing Dictionary, 18th ed., ed. Peter Roach, Jane Setter and John Esling, Cambridge: Cambridge University Press
4. ^ a b The Chambers Dictionary (2008), 11th ed., Edinburgh: Chambers Harrap
5. ^ a b c The American Heritage Dictionary of the English Language (2000), 4th ed., Boston: Houghton Mifflin
6. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
8. ^ Collins English Dictionary (2023), Glasgow: HarperCollins
9. ^ Soanes, Catherine; Stevenson, Angus, eds. (2004), Concise Oxford English Dictionary, 11th ed., Oxford: Oxford University Press
10. ^ a b Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster