Scourge
To whip, beat, or thrash severely. Also as a noun, the instrument of punishment.
Once again, I would have told you that I knew what scourge means. And I would have been generally sort of right. I would have used it in certain contexts as a synonym for threat or to mean a damaging influence.
But when I came across the second Porcian law, which according to [wikipedia](http://en.wikipedia.org/wiki/List_of_Roman_laws), «prohibits scourging of citizens without appeal», it became painfully clear that I had no idea of its specific meaning. Now it’s 2:30 in the morning and I’ve spent the last few hours researching definitions from reading two or three paragraphs earlier this afternoon, including a word I had to look up in the middle of looking up other words! Is there any wonder why I’m nine books behind on my 52-in-52?