consisting of or involving two parts or components usually in pairs
having more than one decidedly dissimilar aspects or qualities
a grammatical number category referring to two items or units as opposed to one item (singular) or more than two items (plural)
a prearranged fight with deadly weapons by two people (accompanied by seconds) in order to settle a quarrel over a point of honor
any struggle between two skillful opponents (individuals or groups)
fight a duel, as over one's honor or a woman
