Welcome to another in my occasional series of obscure insults for unpleasant people. This one isn’t to be wielded lightly — if you hurl it you’re saying your opponent is immoral, grossly criminal, extremely wicked, vile, atrocious, heinous or infamous.
The word comes to us from Latin facinorosus, criminal or wicked, whose base is facinus, a deed, especially a bad one.
It is most commonly to be found in works of the seventeenth century. Shakespeare employed it in As You Like It, though its known history predates him by 50 years; it appeared first in a work by one of the sources for his history plays, the Tudor chronicler Edward Hall. The latter was fond of richly uninhibited adjectives, in this case describing the wickedness of the Yorkist aggressors in the Wars of the Roses.
Facinorous remains too rare for most people to have ever encountered it, though it occasionally and unexpectedly surfaces:
Some people called this man wicked. Some called him facinorous, which is a fancy word for “wicked.”
The Slippery Slope, by Lemony Snicket, 2003.