They're not that evil, are they? Those wonderful, savory, creamy eggs everyone's glad to see on an appetizer tray. They're definitely a member of the new-haute bar snack movement and an old member of the "best Southern foods, ever" club. Then there's deviled ham, also known as ham salad, which is also not evil. Basically the Lucifer-related answer you're looking for isn't here.
To quote a great Food Republic guide to spicy deviled eggs, "to devil" can be defined as such:
Devil: verb. (modern) The act of combining with mayonnaise and seasonings with every intention to serve as an appetizer. (old-school) To coat with a spicy paste, as might allude to Lucifer himself (kind of a stretch).
But it actually comes from an 18th century cookbook to describe anything made spicy with pepper or mustard, pretty much the only seasonings in regular use at the time. And pepper and mustard are both ingredients in our classic Southern deviled egg recipe, which you should definitely try.
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