When the word convince was first used in a 1548 history of the British royal family, it meant "overcome"! That definition died out in the seventeenth century, but a new sense of "to overcome in argument" emerged around the same time, which stuck with us to today. This actually makes a lot of sense if you look at the Latin roots of the word: con- is from the word cum, meaning "with", and the vince part comes from the verb vincere, meaning "to conquer". Finally, cum comes from Proto-Indo-European kom, meaning "beside", and vincere derives from Proto-Indo-European weik, "to fight". Convince is closely related to convict, since someone is convicted when a jury is overcome by the arguments of the prosecution, and conviction, which came to us by a notion of "proof" through overcoming evidence.
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.