When the word college was first used in the late fourteenth century, it had more of a meaning of "group of people performing a common function" (the same sense as in the phrase Electoral College) and the modern definition developed from that. The word comes from Latin collegium, which could mean "guild" or "society" (and is also the source of colleague). Collegium is composed of cum, meaning "with", and the verb legare, "to choose"; it seems that the idea was that business partners make decisions together. Cum comes from the Proto-Indo-European root kom, also meaning "with", and I've written about legare several times before (it's also the source of league, legacy, allege, and legal) - it derives from the Proto-Indo-European root leg, which translates to "collect" or "gather".
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.