Recrudescence – it means something like there was once this bad thing around, and it went away, and now here it is coming back again, thanks a lot! Or the return of some lousy thing we thought we got rid of once and for all.
I was once having an email war with this insane anti-Cuban Zionist Jew from Florida. I forget what it was all about. He went and read one of my articles and saw that word. He wrote me back and he said he had decided that he liked me now after all because I taught him a new word! One of the rare cases where you brain can transform an enemy into a friend.