Vicissitude is a rather euphonious word describing a negative development of any type. It was borrowed in the 1560s from Middle French and became very popular until it really dropped in usage after 1900. The Middle French word was borrowed from Latin vicissitudinem, which meant "alteration", and the root of that is vicis, "change" (this is also the etymon of the Spanish and French words for "time", vez and fois, respectively). Vicis is thought to be from the Proto-Indo-European reconstrction weik, which was a verb with a general meaning of "bend", through a connection of "turning". Weik spawned a whole litany of other terms, like the vice in vice versa or vice president and villa, among others. Such interesting developments and none of them negative- I guess you could say the etymology of vicissitude is far from vicissitudinous!
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.