parabola

Etymology

It is borrowed from New Latin parabola,^{[2][3][4][5][6][7]} from Ancient Greek παραβολή (parabolḗ, “juxtaposition, application”),^[2][5][6] from παραβάλλω (parabállō, “to set side by side”),^[1][8] from παρά (pará, “beside”) and βάλλω (bállō, “to throw”),^[1][9] the latter from Proto-Indo-European *gwele- (“to throw, reach”).^[3] The word is a doublet of parable, palaver and parole.^[4][1] The OED explains that earlier geometers, including Archimedes, called the curve the section of a right-angled cone, and that the geometric name is due to Apollonius of Perga, about 210 BC.^[2][10][5] It referred to the "application" of a given area to a given straight line, without the excess of the hyperbola or the deficiency of the ellipse.^[2][10][4] Eutokius of Ascalon, about AD 550, explained the name differently, by the parallel of the section to a side of the cone, and later writers often repeat that explanation.^[2] The word stands in Latin headings of Archimedes printed in 1544 and 1558,^[2] and the OED compares French parabole (1555), Italian parabola (1556), Spanish parábola (1567) and German Parabel (1525 or earlier).^[2]

Earliest recorded meaning

The conic section: 1559, in Morwyng's translation of Gesner's Treasure of Euonymus,^[2][7] a date from the revised OED.^[2] Barnhart has 1579,^[4] Etymonline the 1570s,^[3] and Dictionary.com 1570–80.^[11]

Semantic evolution

From 1664 the name also covered plane curves of a higher degree with branches that do not approach asymptotes.^[2][12] Since 1841, in Emerson, it has also meant any similar curve, especially the path of something moving through space or time, including figurative arcs.^[2] French has the trajectory use from 1727.^[2] A separate rhetorical sense, a comparison or simile, appears in 1577 in Peacham's Garden of Eloquence and is now rare; it goes back to the use of the Greek and classical Latin nouns for comparison or illustration in Aristotle and Quintilian.^[2] Johnson (1755) defines the conic section after Harris and quotes Bentley on the paths that planets would follow at other speeds.^[13] Merriam-Webster Unabridged also has the name for a bowl-shaped microphone or antenna.^[7]

Timeline

• 1559 – in mathematics, the open curve formed when a plane cuts a cone parallel to its side.^[2][7] Barnhart first finds it in 1579.^[4]
• 1577 – in rhetoric, a comparison or simile.^[2]
• 1664 – in mathematics, a similar curve of higher degree.^[2]
• 1841 – any similar curve, especially a trajectory, also figuratively.^[2]

Meanings

Noun

1. In mathematics, the open curve made when a plane cuts a cone parallel to its side; the set of points equally distant from a fixed point, the focus, and a fixed line, the directrix.^{[14][7][2][12]}
2. More broadly, a plane curve of higher degree that resembles this one.^[2][12]
3. Any similar curving path or shape: The flare traced a long parabola over the bay.^[2]
4. A bowl-shaped microphone or antenna.^[7]
5. (rare) In rhetoric, a comparison or simile.^[2]

Word family

• paraboloid

Related words

• parable
• palaver
• parole
• parlor
• hyperbola
• parabolic

References

1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
6. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
7. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
9. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
10. ^ a b Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
11. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
12. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
14. ^ Collins English Dictionary (2023), Glasgow: HarperCollins