duel

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A prearranged, formal combat between two persons, usually fought to settle a point of honor.
2. n. A struggle for domination between two contending persons, groups, or ideas.
3. v. To engage (another) in or as if in formal combat.
4. v. To oppose actively and forcefully.
5. v. To engage in or as if in formal combat.

Century Dictionary and Cyclopedia

1. n. A single combat; specifically, a premeditated and prearranged combat between two persons with deadly weapons, and usually in the presence of at least two witnesses, called seconds, for the purpose of deciding a quarrel, avenging an insult, or clearing the honor of one of the combatants, or of some third party whose cause he champions. The origin of the modern practice of dueling was doubtless the judicial combat or wager of battle resorted to in the middle ages as a means of settling disputes. The practice was formerly common, but has generally been suppressed by adverse public opinion in civilized countries. In England and the United States dueling is illegal, death resulting from this cause being regarded as murder, no matter how fair the combat may have been; and the seconds are liable to severe punishment as accessories. Deliberate dueling is where both parties meet avowedly with intent to murder. In law the offense of dueling consists in the invitation to fight; and the crime is complete on the delivery of a challenge.
2. n. Any fight or contest between two parties; especially, a military contest between parties representing the same arm of the service.

Wiktionary

1. n. Arranged, regular combat between two private persons, often over a matter of honor.
2. n. Historically, the wager of battle (judicial combat)
3. n. Any struggle between two contending persons, groups or ideas.
4. v. To engage in a duel.

GNU Webster's 1913

1. n. A combat between two persons, fought with deadly weapons, by agreement. It usually arises from an injury done or an affront given by one to the other.
2. v. obsolete To fight in single combat.

WordNet 3.0

1. n. a prearranged fight with deadly weapons by two people (accompanied by seconds) in order to settle a quarrel over a point of honor
2. n. any struggle between two skillful opponents (individuals or groups)
3. v. fight a duel, as over one's honor or a woman