When the word monkey was borrowed into English in the 1530s, there was no standard way of writing it. Spellings included monkaie, munckey, munkai, menkeie, munkkey, moncky, munkie, and many others. The reason for all the confusion is that it was borrowed from an unrecorded Dutch word, so scholars had to figure out how to spell it on their own. In the language, it probably sounded something like monnekjin, and that's thought to be from Spanish mono, meaning "monkey". Mono is thought to be a shortening of Old Spanish maimon, which was borrowed from Arabic maymun, still "monkey" (as a Serbian speaker, it's cool to see the connection to their word, majmun). Finally, that's thought to be related to the Proto-Semitic root y-m-n, "right", but the etymology is uncertain.
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.