defeat

Etymology 1

From Middle English defeten, from Middle English defet (“disfigured”, past participle) and defet (“defect”, noun), see Etymology 2 below.

verb

1. (transitive) To overcome in battle or contest.
   Wellington defeated Napoleon at Waterloo.
   The Japanese defeated the Ming general Tsu Chʻeng-hsün 祖承訓 at Pʻing jang 平壤 in 1592, the first year of Bunroku 文祿 of Japan, and the fighting continued for some years; but at Hideyoshi's death the Japanese troops left Korea. 1917, Samuel Couling, “Japanese Relations with China”, in The Encyclopaedia Sinica, Literature House, Ltd., published 1964, →OCLC, page 255, column 2
   My personal success or failure is insignificant; the rise or fall of the nation is my responsibility and must not be shirked. Upon introspection, I feel I am firmer than ever in confidence that the Communists will be defeated. These are feelings which will comfort Father's soul in Heaven. August 01, 1980 [1 May 1980], Ching-kuo Chiang, “President Chiang Ching-kuo continues his period of mourning and finds that visits to countryside and people give him renewed strength”, in Taiwan Today, archived from the original on 2020-05-17
2. (transitive) To reduce, to nothing, the strength of.
   In one instance he defeated his own purpose. 1879, Adolphus Ward, “Chaucer”, in English Men of Letters
3. (transitive) To nullify
4. To prevent (something) from being achieved.
   The last active L.Y.R. 0-6-0ST (apart from works shunters), No. 51408, has been moved from Bolton to Agecroft for use in New Bailey Yard, Salford, where a sharp 1 in 27 curve is said to have defeated all attempts so far to employ diesel shunters; an ex-L.Y.R. 0-4-0ST also works here. 1962 January, “Motive Power Miscellany: London Midland Region: Central Lines”, in Modern Railways, page 60

Etymology 2

From Middle English defet, from French deffet, desfait, past participle of the verb desfaire (compare modern French défaire), from des- + faire.

noun

1. The act or instance of being defeated, of being overcome or vanquished; a loss.
   Licking their wounds after a temporary defeat, they planned their next move.
   Two defeats in five games coming into this contest, and a draw with Everton, ultimately cost Sir Alex Ferguson's side in what became the most extraordinary finale to the league championship since Arsenal beat Liverpool at Anfield in 1989. May 13, 2012, Alistair Magowan, “Sunderland 0-1 Man Utd”, in BBC Sport
2. The act or instance of defeating, of overcoming, vanquishing.
   The inscription records her defeat of the country's enemies in a costly war.
3. Frustration (by prevention of success), stymieing; (law) nullification.
   ... is subsequently issued to him, in accordance with his perfect equity thus acquired, by a legal fiction which the law creates for the protection, but not for the defeat, of his title. 1909, The Southern Reporter, page 250
   She could see no justice in being forced into a position that promised to end in further humiliation and defeat of her hopes. 2008, Gene Porter, A Daughter of the Land, volume 1, page 17
4. (obsolete) Destruction, ruin.