xi

Pronunciation

• IPA: /zaɪ/, /saɪ/^[1]

Etymology

It is borrowed from Ancient Greek ξῖ (xî), the name of the fourteenth letter of the Greek alphabet.^[2][3][4]

Earliest recorded meaning

The Greek letter: by the early 15th century in Etymonline, the 15th century in MWU.^[2][3]

Semantic evolution

In physics, either of a pair of hyperons, the xi particles, is from 1954.^[5][6]

Timeline

• early 15th century – the Greek letter.^[2]
• 1954 – the xi particle.^[5]

Modern meaning

Noun

1. The fourteenth letter of the Greek alphabet (Ξ, ξ), transliterated as x.
2. (physics) A xi hyperon.

Related words

• xenon
• alphabet

Usage notes

Collins gives several pronunciations: /zaɪ/, /saɪ/, /ksaɪ/ and /ksiː/.^[7] The Xi is also a river of southern China.^[7]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ Pearsall, Judy, ed. (1998), The New Oxford Dictionary of English, Oxford: Clarendon Press
5. ^ a b Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
6. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
7. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins