Paris. Somehow everybody wants to go there. This famed "City of Lights" may not be as... clean as people may think. The word for the city can be traced farthest back to the Proto-Indo-European word leu, meaning "dirt". This later became lhuto, still meaning "dirt", and then dawdled around in Proto-Italic for a bit (hiding under the pseudonyms luto and lustro). Eventually history went ahead and grew up a few thousand years, and the word found its way into Latin as lutum, "dirt, mud, or clay". Subsequent to this came the Latin word Lutetia, meaning "swamp", a reasonable transition from "mud" (Note: one of my sources says this whole explanation is a bunch of armadillo dung, and the word actually came from Gaulish). When the Romans went and conquered Paris in 52 BCE, they named it Lutetia Parisorum, or "swamp of the Parisii tribe" (which probably got its name from Celtic). Eventually, as the Romans left the area, people decided that was a mouthful, so they dropped the Lutetia and the -orum, leaving us with just part of an adjective that used to belong to a larger whole. So forget the "City of Lights", and visit the "dirty tribal town"!
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