The Etymologicon: A Circular Stroll through the Hidden Connections of the English Language

Wagering War

You can’t really wage anything other than war. You can try, but it sounds rather odd. Indeed, the phrase waging war gets stranger the more you look at it. Does it have anything to do with wages, or wage disputes, or maybe freeing the wage slaves? There’s a connection between all these different wages, and indeed to wagers. But you have to go back to the fourteenth century.

A wage was, originally, a pledge or deposit. Wage is simply a different way of pronouncing the gage in mortgage and engagement.[29] A wage was something given in security. From this wage you quite easily get to the modern wager: it’s merely the stake, or deposit, thrown down by a gambler. It’s also reasonably simple to see how money given in security could end up meaning money given as pay. But waging war? That involves trial by combat.

In medieval law it was considered quite reasonable to settle a legal dispute by duelling to the death. Though somebody had to die in this system and there was no guarantee of justice, lawyers’ fees were at least kept to a minimum.

A wronged medieval man would throw down his gage/wage (or pledge), and challenge his opponent to trial by combat. In Latin that was vadiare duellum; in French it was gager bataille; in English you waged [pledged yourself to] battle.

Not war. Battle. It was, after all, a technical legal term for the violent resolution of individual arguments. You wagered your body in mortal combat. However, it’s easy to see how the sense of waging battle extended from the promise of violence to the act of violence.

In the end, when two countries couldn’t agree, they started waging war against each other. This last shift in meaning could reasonably be described as wage inflation.