n.
 chiefly historical a prearranged contest with deadly weapons between two people to settle a point of honour. 
▸(in modern use) a contest between two parties.
v.
 (duels, duelling, duelled; US duels, dueling, dueled)
 fight a duel.
Derivative
  
    - dueller 
(US dueler)
 n.
- duellist 
(US duelist)
 n.
 
  Etymology
  C15: from L. duellum, archaic and literary form of bellum ‘war’, used in med. L. with the meaning ‘combat between two persons’, influenced by dualis ‘of two’.