Remember back in the unicorn post, where I proved that cornus is Latin for "horn"? Well, you might notice that the same root is present in cornucopia. It literally comes from Latin cornu copiae, or "horn of plenty". This mythologically referred to the goat horn that the baby god Jupiter ate out of. As we've already seen, cornu goes back to Proto-Germanic hurnaz, from Proto-Indo-European ker, meaning "horn" or sometimes "head". Copiae, the latter component of the word (which you may recognize as being related to copious; it is, through copiosus, "plentiful"), has different etymologies proffered at my different sources; it could be from com, "with" (from PIE kom, "beside"), or the prefix co- added to the root opis, meaning "wealth" (from PIE hep, "to work", because you work to earn wealth). The second theory makes more sense, I think, but etymology rarely makes sense, so it might as well be the first.
Adam Aleksic has been described as the internet's sixth most famous etymologist. He loves writing about himself in the third person, he's a freshman at Harvard University, and he has disturbing interests in linguistics, vexillology, geography, board games, limericks, and law.
The Etymology Nerd