The other day, Jim and I were looking at a eucalyptus tree, and I realized that although the eu- part was obvious, I had no idea what the -calyptus part meant.
So I looked it up. It is awfully nice to have a dictionary on my cell phone.
New Latin, genus name, from eu- + Greek kalyptos covered, from kalyptein to conceal; from the conical covering of the buds
Which is kind of interesting, and good to know, but that wasn't the part that caught my eye. The surprising part was this:
—more at HELL
So I checked the etymology for hell, and sure enough:
akin to Old English helan to conceal, [. . .] Greek kalyptein
So there you have it: eucalyptus and hell are distantly related, by way of a Greek word for concealment.
I'm pretty sure this wins the most surprising-to-me etymology of the year award.