verb (duels, dueling, dueled ; Britishduels, duelling, duelled)[no object]
late 15th century: from Latin duellum, archaic 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 honor' dates from the early 17th century
Do not confuse duel with dual. See dual.