Occasionally we get words for types of buildings named after a specific building, like with morgue, capitol, and academy. Bastille is an example of the opposite: a specific building named after a type of building. The term, which today only refers to a former fortress in Paris or the band named after it, could once be applied to any tower or fortified encampment, just like its relative bastion. This most likely comes from the thirteenth-century Old Occitan word bastida, meaning "fortress", and that's from the Old French verb bastir, which could mean a lot of things, including "to build" (the sense used here), "to sew", "to prepare", and "to baste" (this is also the source of English baste). Finally, it's all reconstructed to a Proto-Germanic word also meaning "to baste".
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.