The word profane first entered English in the mid-fifteenth century with the spelling prophane and referred to things that were unholy, unclean, or pagan. It comes from the Latin verb profanare, meaning "desecrate". More literally, though, it meant "out in front of the temple", because people considered profane were not admitted into Roman temples. The roots there are the prefix pro-, meaning "before" (from Proto-Indo-European per, also "before") and the noun fanum, meaning "temple" (also the source of the word fanatic; comes from the Proto-Indo-European reconstruction dehs, which could mean either "god" or "sacred place". Meanwhile, the word profanity was coined around the early seventeeth century from profane and only started getting widely used in the nineteenth century.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.