Another word request, and a fun one to do! Far before Engles and Marx popularized the word proletariat, making it near synonymous with communism, it has quite a different meaning. The farthest back it can be traced is to Proto-Indo-European, where it was proal, or "grow forth". In Latin this eventually got picked up as proles, and it actually meant "children" or "offspring" (today the precursor of progeny and prolific). In a later, special edition double-Latinized word, the Romans tacked on the ending -ian (a suffix talking about a person, with a much more boring history but also from PIE) to make proletarian. This is an actual word which still exists today, so naturally it wasn't difficult for this to pass into French as prolétariat, which described a group of people who were lower class, a definition already in place from the Romans, who loved taking nice words and making them mean. This then became the English word proletariat in the 1850s, became associated with communism only a few years later, and lived happily ever after.
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