The etymology of burrito is really obvious, but nobody stops to think about it, as it's basically become a single morpheme at this point. Since -ito is a Spanish suffix meaning "little", burrito means a "tiny burro", or a "tiny donkey" (pretty macabre; that's probably what kind of meat stuffed the original burritos). Burro comes from the earlier Spanish word with the same definition, burrico, which stems from Latin, as many Romance language words do; in this case from the word burricus, which was a type of horse- not much of a change. Since the burricus horse was tinted chestnut, it makes sense that burricus would come from the Latin word for "reddish-brown", burrus. By similar logic, since fire is sort of reddish, it also is unsurprising that this comes from the Greek word for "fire", pyrros. from pur ("fire"), which derives from the Proto-Indo-European term pehwr, or "bonfire". It's amazing how these three words, so hard to connect by heuristics, make perfect sense when considered from a step-by-step point of view.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.