Q From Mike Davis in California: I’d like to know the origin of the phrase to carry the can
A This is another of those odd expressions that’s best known in British English. If you carry the can for something you’re bearing the responsibility for its having gone wrong, often with the implication that you’re taking the blame for someone else. A good example appeared in the Times in 1957: “Senior officers who were forced to ‘carry the can’ because of the misdeeds of others”.
It’s particularly relevant because we’re fairly sure the expression derives from services’ slang. The first recorded cases are from the Royal Navy in the late 1920s, though Eric Partridge, in his Dictionary of Historical Slang, says it had been around since the late nineteenth century. In his Dictionary of Forces’ Slang he suggests that the idiom refers to “the member of a gang or party who fetches the beer for all and then has the melancholy task of returning the empty”. The job of carrying the group’s ration of beer was obviously one that laid you open to much unpleasantness if you spilled any or dropped the can.
There’s an older slang expression that’s probably relevant: to carry the keg, also as to carry the cag. Cag and keg are variants of the same dialect word, meaning to offend or insult (cag or kag was also once British Navy slang for one of those arguments in which everybody is shouting and no one is listening). To carry the cag then was to hold a grudge, or to be easily annoyed or unable to take a joke. There’s an obvious pun in the phrase on keg, a small cask, being something that you literally might carry, as you would figuratively carry a grudge.
It may be that carry the can developed as a joking reference to the older idiom, but then took on a life of its own.