rhea

Etymology

It is borrowed from New Latin Rhea, the scientific name of the genus,^[2][3][4][5] which P. H. G. Moehring gave it in his “Avium Genera” of 1752,^[2][6] from Latin Rhea,^[2][3][7] from Ancient Greek Ῥέα (Rhéā),^[2][3][8] the name of a Titaness in Greek mythology, the daughter of Uranus and Gaia, wife and sister of Cronus, and mother of Zeus and other gods.^[2][9][3] Why the bird was named after her is not known: Etymonline says "for unknown reasons",^[9] Hoad calls it an arbitrary use of the myth,^[10] and Partridge a fanciful one.^[11] The name of the goddess is itself of uncertain origin;^[8][9] Partridge notes that the Stoic Chrysippus derived it from the Greek verb for "to flow", because rivers flow from the earth.^[11] The goddess's name was also given to a moon of Saturn discovered in 1672.^[9][12]

Earliest recorded meaning

Either of the two large flightless birds of South America that make up the genus Rhea: first recorded, with a queried date of 1787, in W. F. Mavor's New Dictionary of Natural History.^[2] Merriam-Webster Unabridged also dates the word to 1787,^[5] while Barnhart and Etymonline give 1801.^[3][13][9]

Semantic evolution

The English word has kept its zoological meaning since the late 18th century.^[2][7] It names either of two species: the greater or grey rhea, Rhea americana, and the lesser or Darwin's rhea, which the Shorter Oxford places in a genus of its own.^[7][12] Dictionaries describe the birds as smaller relatives of the African ostrich, with three toes and a fully feathered head and neck,^[5][12] and Etymonline glosses the word as the "three-toed South American ostrich".^[9] Capitalised, Rhea remains the name of the genus.^[5][14]

Timeline

• 1787 – either of two flightless South American birds of the genus Rhea.^[2][5] Barnhart and Etymonline date the word to 1801.^[3][9]

Meanings

Noun

1. Either of two large, fast-running, flightless birds of the open plains of South America, related to but smaller than the ostrich, with three toes and a fully feathered body.^[12][5][2]
2. Rhea (capitalised): the genus of these birds.^[5][14]

Usage notes

The bird is also called a nandu or nandoo.^[12] A separate noun rhea, borrowed from Assamese, is recorded from 1837 for the ramie plant and other plants of the genus Boehmeria, grown for their fibre.^[2][7][5]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
5. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
7. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
10. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
11. ^ a b Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
12. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins
13. ^ Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
14. ^ a b Gove, Philip Babcock, ed. (1961), Webster's Third New International Dictionary of the English Language, Unabridged, Springfield, Mass.: G. & C. Merriam