Treacle is how British people say molasses, and treacle tart is Harry Potter's favorite dessert. Well, it's origin gets pretty wild. Before people realized that treacle was a great sugar substitute, they believed that it could be used as an antidote to snake venom. This was so extreme that, earlier, as the French word triacle, its literal meaning was "antidote" (again with an emphasis on serpents). With the same definition, this came from the Latin word theriaca, which came from the Greek word theriake. This is a conjugation of theriakos, a term meaning "of, or pertaining to, wild beasts" (through a connection of "bite"). Theriakos further comes from ther, which meant "beast" in general. That, through Proto-Italic kwher, derives from the Proto-Indo-European reconstruction ghwer, still with connotations of "wild animal". I'm never going to read Harry Potter the same way again now that I know Hagrid makes tart out of wild animals...
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd