Question

duel 【duel】n.决斗；相斗They decided to settle their quarrel by a duel.他们决定以决斗来解决他们的纷争。

Accepted Answer

['duːəl] 
duela prearranged fight with deadly weapons by two people (accompanied by seconds) in order to settle a quarrel over a point of honor
A duel is a fight between two people, usually using swords or other weapons. If you tend to be a little cowardly, you're probably glad that people aren't expected to defend their honor with a duel these days.
The classic definition of a duel is the kind that happens all the time in Shakespeare plays: two men clanking swords together in a battle to the death over some issue of honor or betrayal. Today, the word duel can be used to talk about any kind of contest or struggle — like a duel between political candidates. The word duel can be traced back to both duo, Latin for "two," and also duellum, which means "war."
All forms of 'duel' will appear on average once every 531 pages.duelduelerduelistduellerduellist
CHOOSE RIGHT WORDS: DUAL-DUEL
			
  Seeing double? Not quite! Dual is two, or  double, but a duel is a fight. If you're getting sick of your  fair-weather friend's dual personality, perhaps you should throw down  your glove and challenge him to a duel at high noon. 
Dual, which dates from the early 1600s, is borrowed from the Latin dualis, from duo, for two. Dual still means double or two similar parts:

The ego becomes dual, one  part active, the other watching and judging. (Max Simon Nordau) 
  Last night's game had kind of a dual purpose — playing Oregon and sending out this version of Husky Stadium. (Seattle  Times)

Duel once  referred to an arranged, formal contest to the death between two people,  preferably men with handlebar mustaches. These formal contests are no longer  practiced, so duel has broadened to mean any contest between two people,  teams, or even ideas:

In early days a properly  regulated duel was an ordeal showing the judgment of heaven. (Max Simon  Nordau)
  In a savage duel between the regime and Islamist guerrillas, entire villages were wiped out. (Business  Week)
  
    There are dueling pension propositions on Tuesday's ballot. (Washington Post)

Save dual for double, for  things that come in pairs, like your hot/cold friend with the dual personality.  Use duel for an old timey sword fight, or any modern version of it.  Handlebar mustache not required.

Front	duel
Pron	['duːəl]
Back	【duel】 n.决斗；相斗 They decided to settle their quarrel by a duel. 他们决定以决斗来解决他们的纷争。
Vocab	duela prearranged fight with deadly weapons by two people (accompanied by seconds) in order to settle a quarrel over a point of honor A duel is a fight between two people, usually using swords or other weapons. If you tend to be a little cowardly, you're probably glad that people aren't expected to defend their honor with a duel these days. The classic definition of a duel is the kind that happens all the time in Shakespeare plays: two men clanking swords together in a battle to the death over some issue of honor or betrayal. Today, the word duel can be used to talk about any kind of contest or struggle — like a duel between political candidates. The word duel can be traced back to both duo, Latin for "two," and also duellum, which means "war." All forms of 'duel' will appear on average once every 531 pages. duel dueler duelist dueller duellist CHOOSE RIGHT WORDS: DUAL-DUEL Seeing double? Not quite! Dual is two, or double, but a duel is a fight. If you're getting sick of your fair-weather friend's dual personality, perhaps you should throw down your glove and challenge him to a duel at high noon. Dual, which dates from the early 1600s, is borrowed from the Latin dualis, from duo, for two. Dual still means double or two similar parts: The ego becomes dual, one part active, the other watching and judging. (Max Simon Nordau) Last night's game had kind of a dual purpose — playing Oregon and sending out this version of Husky Stadium. (Seattle Times) Duel once referred to an arranged, formal contest to the death between two people, preferably men with handlebar mustaches. These formal contests are no longer practiced, so duel has broadened to mean any contest between two people, teams, or even ideas: In early days a properly regulated duel was an ordeal showing the judgment of heaven. (Max Simon Nordau) In a savage duel between the regime and Islamist guerrillas, entire villages were wiped out. (Business Week) There are dueling pension propositions on Tuesday's ballot. (Washington Post) Save dual for double, for things that come in pairs, like your hot/cold friend with the dual personality. Use duel for an old timey sword fight, or any modern version of it. Handlebar mustache not required.

Duel Dual Honor People Kind Contest Settle Quarrel