There is no rage in outrage.
If you were to tell me that I was outside the norm, beyond moderation, extravagant, and strangely dressed, I would be outraged!
And I’d probably agree with you. But even if I didn’t agree, I wouldn’t necessarily be angry about your claim.
You see, when the word outrage and its derivatives came to us in Middle English from Old French, it had nothing to do with rage at all. So you can see what I mean, let’s split the word into two syllables.
Out-rage. Right?
Wrong—at least when the word started out. Let’s return one of the original letters to the word and try that split again: outre-age.
Outre is an Old French word meaning “beyond.” And the state of beyondness was outre-age, somewhat along the lines of the state of draining being drainage, the state of assembling being assemblage, and the state of messing being message (well, I made that last one up).
The original outrage, before we borrowed it into English around the 1300s, was something “beyond” propriety—an insult or some other transgression. When we brought it into English, outrage had intensified beyond (or outre) mere impropriety to insolence or even violence. To be outraged in the early 1700s was to be violated; by the 1800s, to be appalled or, in a common modern sense, to be infuriated, enraged.
By the way, a side note: outrageous is outrageously verbose. If something is outrageous in the modern sense of the word, it is also—simply and sleekly— outre.