It almost feels like the words prequel and sequel were coined at the same time. Likewise, it seems like prequel has been around as a word forever. Both of these are incorrect misconceptions; prequel was actually coined in 1973 and patterned off the pre-existing word sequel, which had been around since the 1400s. It's mind-boggling to me that we didn't have a word for it before then. Sequel derives from Middle French sequelle, from Latin sequella, from the verb sequor, meaning "to follow". This, through Proto-Italic sekwor, can be reconstructed as coming from the Proto-Indo-European root sek, also "to follow". So se- was never a prefix, but part of the word, and the insertion of pre- mistakenly assumed that it was one. Pre- comes from Latin prae, "before", which is from Proto-Indo-European preh, meaning "before". So a prequel is "before following". Sequel is still used a lot more, but only because there are more prequels out there. It only took a few years for prequel to catch on as a normal word.
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.