The definition I immediately associate with the word default is "preselected option", but this is actually a really new meaning! In fact, when the word first started showing up in English in the thirteenth century, it meant "transgression" or "sin". This spawned a new sense of "doing something incorrectly", which evolved into "failure to do something one was supposed to do" - the reason one defaults on a mortgage and the reason a sports team can win a game by default if the other team doesn't show up. In the 1960s, computer scientists needed a name for the value that was output when there was no input, and so they called this the default setting, which is how we got that definition. The word comes from Old French defaulte, meaning "deceit", and that's from the Latin prefix de- ("away") and the root fallere, meaning "to cheat" or "deceive". That also gave us words like false, fail, fault, and fallacy, and is ultimately of unknown origin.
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.