Thursday has one of the more widely known etymologies of the days. Throughout Middle and Old English, it took on various forms such as thuresday, thursdæg, thunresdæg, thurresdæg, and thunresdæg. However, though, this word in all of its forms can ultimately be broken down into its Old English components: thunre, the spelling of "Thor" at the time, and dæg, which we've already covered as meaning "day". In Proto-Germanic, thunre was thunraz, who was sort of a hybrid god of Thor and Jupiter (in most Romance languages, the fifth day of the week is normally named after Jupiter), similar to the Mercury/Odin split for old words for Wednesdays. It's weird. The literal meaning of thunraz was "thunder", and it retained this definition from its Proto-Indo-European progenitor, tenh. Dæg comes from Proto-Germanic dagaz, from PIE deg, or "to burn", as we've already covered in yesterday's post. So Thursday's hidden meaning is "burning thunder".
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