Etymology From Medieval Latin duellum (“fight between two men, duel”), itself from Old Latin duellum (“war, fight”), which survived in Classical Latin as a rare byform of bellum and was later reinterpreted as “duel” by unetymological association with duo (“two”). May have entered English through Middle French duel.
1
Arranged, regular combat between two private persons, often over a matter of honor.
I have often thought since, how different my fate might have been, had I not fallen in love with Nora at that early age; and had I not flung the wine in Quin’s face, and so brought on the duel.1844 January–December, W[illiam] M[akepeace] Thackeray, “In Which I Show Myself to Be a Man of Spirit”, in “The Memoirs of Barry Lyndon, Esq. [The Luck of Barry Lyndon.]”, in Miscellanies: Prose and Verse, volume III, London: Bradbury and Evans, […], published 1856, →OCLC, page 36:
Of course, not all the Railway Members were men of such talent. One member was "chiefly eminent as a whist player," and another was known for his duel with a fellow M.P. fought at Wormwood Scrubs in 1840.1960 March 23, N. Caplan, “The Railway Member of Parliament”, in Railway Magazine, page 209:
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It has been 200 years, minus a few days, since Vice President Aaron Burr fatally shot Alexander Hamilton in a duel here. Weehawken and the duel have been tied together in an often-uncomfortable knot ever since.2004 July 5, Jason George, “A Duel Evokes Dueling Emotions Over a Unique Place in History”, in The New York Times, →ISSN, archived from the original on 05 Nov 2018:
After Rep. William Graves of Kentucky killed Rep. John Cilley of Maine in a duel in 1838, Congress imposed a prohibition on pistol duels in the District of Columbia.2017 June 14, Julian Zelizer, “The challenge of protecting members of Congress”, in CNN, archived from the original on 14 Jun 2017:
2
Historically, the wager of battle (judicial combat).
3
Broadly Any battle or struggle between two contending persons, forces, groups, or ideas.
a sniper duel
But it leaves them with a few destroyers, the American destroyer force is falling back, and then you have the two cruiser lines with their respective battleships coming in for the big duel.2019 March 6, Drachinifel, 25:33 from the start, in The Battle of Samar (Alternate History) - Bring on the Battleships!, archived from the original on 20 Jul 2022:
1 more example
Apple comes out swinging in the duel of the data titans [title]2021 May 1, John Naughton, “Apple comes out swinging in the duel of the data titans”, in The Guardian, archived from the original on 21 Oct 2021:
duel
verb
Etymology From Medieval Latin duellum (“fight between two men, duel”), itself from Old Latin duellum (“war, fight”), which survived in Classical Latin as a rare byform of bellum and was later reinterpreted as “duel” by unetymological association with duo (“two”). May have entered English through Middle French duel.
1
To engage in a battle.
The two dogs were duelling for the bone.
The country’s fencing federation has officially recognised lightsaber duelling as a competitive sport, granting the weapon from George Lucas’s space saga the same status as the foil, epee and sabre, the traditional blades used at the Olympics.2019 February 19, “Lightsaber duelling registered as official sport in France”, in The Guardian, archived from the original on 08 Nov 2020: