@medicchristy: It is said that there was an Englishman by the name of William Underwood who owned a condiment business in 1822 on Boston’s Russia Wharf. After a while, the family started experimenting with different products created from ground ham blended with special seasonings. They started seasoning different foods and the seasoning process came to be known as “deviling”. That is where the Underwood “red devil” came from.
Since then, “deviling” is considered to be a food that has something added to it to give it a kick. Things like hot sauce, cayenne pepper, paprika, and Dijon mustard are an example of things that are used to “devil” food. Hence, deviled eggs came to be.