Pardon the pun, but the word pollution has a surprisingly dirty etymology. It wasn't until the 1860s that the word meant "environmental contamination"; before that it had the very specific definition of "semen released anytime other than during intercourse", often referring to nocturnal emissions. Obviously this is connected to the modern word through a sense of contamination, but where does it come from? The source in question is Latin pollutionem, which had a bit broader meaning of a "defilement" or "desecration" of any kind. This nominative can be conjugated into the verb polluere, which meant "to defile" and was composed of two parts: por-, meaning "before", and luere, meaning "to smear." Essentially, "before smearing". Make your own inferences. Por- comes from the Proto-Indo-European root per, with the same definition and luere comes from Proto-Indo-European leu, or "to make dirty".
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.