“Felon” might be more of an insult than you think. Its meaning, like the meaning of so many legal words, is much less refined and academic than many of us would assume.
The noun “felon” was first adopted by the English language around 1300, to mean “an evil-doer, or someone who deceives, commits treason; is wicked, or is evil.” The word was used to describe Lucifer and Herod. It comes from the Old French word of the same spelling that first began use in the Ninth Century. This word, which has the same meaning as its English descendant, comes in turn from the Medieval Latin “fello.” This means “evil-doer” but is itself of uncertain origin. Some have proposed that it comes from the Frankish “Fillo” which means “person who whips or beats, scourger. This word went a different path in the German language, and became the source of the Old High German “fillen,” meaning “to whip.”
Others propose that the Latin “fel” is the source of “felon.” “Fel” means “gall” or “poison,” with the connotation of a bitter person. Still others propose Celtic origins.
But the origin of “felony” may be more vulgar and more interesting than all of these. Philologist Robert Atkinson worked at Trinity College in Dublin. He was a university professor of Romance Language, had the chair of Sanskrit, and also the chair of comparative philology. In addition to the Latin and the Romance languages, he spoke Sanskrit, Tamil, Telugu, Hebrew, Persian, Arabic, several languages of Central and Western Asia, and other Indian vernacular languages. He was also an botanist, amateur violinist, and jujitsu enthusiast. I mention this so that the reader can be assured that this is a Very Serious Man. Atkinson traced “felon” to the Latin “fellare” meaning “to suck.” This, of course, has an obscene secondary meaning in classical Latin. Readers of Martial and Catullus will know that “felon” in this sense, is derived from “cock-sucker.”
For example, here is a conjugated version of “fellare” in Martial:
Quod fellas et aquampotas, nil, Lesbia, peccas: / qua tibi parte opus est, Lesbia, sumis aquam.
Because you suck [cock] and drink water, Lesbia, you err in nothing: / in just the part you ought to be, Lesbia, you’re making use of the water.
(Martial, Epigrams 2.50.)
Or in Catullus:
Bononiensis Rufa Rufulum fellat
Rufa of Bononia sucks Rufulus
(Catullus, Poem 59.)
“Fellatio” is derived from this usage of the word “felon,” but retains some of the original sense, even though it was not coined until 1894 by Havelock Ellis. Despite being a virgin until the age of 32 and suffering from impotence, Ellis was somehow considered a sex expert and has a Wikipedia entry that is definitely worth reading. The word, “homosexual” is attributed to him.
At the same time that “felon” was coming into use in English, it was also being used in a general legal sense to mean “criminal” or “someone who has committed a felony.” The term was not applicable after legal punishment was completed. Australian official James Mudie coined the term “felonry” around 1837. It means “an order or class of persons in New South Wales, — an order which happily exists in no other country in the world.” “Felony,” predictably, means “treachery, betrayal, deceit, villainy, wickedness, sin, crime, wrath, ruthlessness, or evil intention.” As a class of crime in common law, the exact definition has changed over time and place. Even the distinction from misdemeanor or trespass is not always observed. In old use, “felony” was often a crime involving forfeiture of lands, goods, or punishable by death. Someone who commits suicide is called a “felo-de-se,” meaning literally “one guilty concerning himself.”