(in the past 舊時 a formal fight with weapons between two people who disagreed, especially over a matter of honour （舊時爲解決紛爭的）決鬥 to fight/win a duel 進行／赢得決鬥 to challenge somebody to a duel 要求與某人決鬥
Extra ExamplesHe fought a duel with the prince. 他和王子進行了一場決鬥。 a duel between the two officers 兩名軍官之間的決鬥
a competition or struggle between two people or groups （雙方的）競爭，鬥爭 The debate rapidly descended into a verbal duel between the two candidates. 這場辯論很快演變成兩位候選人之間的口頭決鬥。
Word Originlate 15th cent.: from Latin duellum, archaic and literary form of bellum ‘war’, used in medieval Latin with the meaning ‘combat between two persons’, partly influenced by dualis ‘of two’. The original sense was ‘single combat used to decide a judicial dispute’; the sense ‘contest to decide a point of honour’ dates from the early 17th cent.