nefarious

adj

Etymology: From Latin nefārius (“execrable, abominable”), from nefās (“something contrary to divine law, an impious deed, sin, crime”), from ne- (“not”) + fās (“the dictates of religion, divine law”), which is related to Latin for (“to speak, to say”) and cognate to Ancient Greek φημί (phēmí, “to say”).

1. Sinful, villainous, criminal, or wicked, especially when noteworthy or notorious for such characteristics.

   “Aliens have a nefarious connotation in many science fiction books.”

   “"If the vessel be no fair-trading slaver, nor a common cruiser of his Majesty, it is as tangible as the best man's reasoning, that she may be neither more nor less than the ship of that nefarious pirate the Red Rover."”