I really like today's "Word of the Day" (http://wordsmith.org/words/recrudescence.html). Not because I'm likely to be about to experience it (though I'd like that & am secretly in my heart of hearts trying for it) but for its etymology, which was completely surprising after its meaning:
noun: A renewed activity after a period of dormancy.
From Latin recrudescere (to become raw again), from re- (again) + crudescere (to get worse), from crudus (raw). Earliest documented use: 1665.