(Latin: duellum, old form of bellum, war)
A contest with deadly weapons between two persons to settle a private quarrel, usually over an insult or wounded honor.
It is of heathen origin but was so deeply rooted in the habits of converted nations that the Church had to use most severe measures to stop it.
As governments became more civilized and as the evil grew they too had to do their utmost to suppress it.
It is a rare practise today, as both civil and religious authorities have impressed on men how contrary it is to common sense.
It involves the double crime of murder and of suicide, victor and victim each intending the death of the other and each imperiling life without due reason.
New Catholic Dictionary