A good five years ago, I had a spat with my neighbor about whether or not truffles was named after a city in France. The debate was unresolved, but I can now claim a victory to my argument! According to my sources, the word truffle definitely comes from French, and the word trufle, which referred to the mushroom specifically. This came from Old Provincial, apparently a dialect of French, where it was either trufa, truffe, or something along those lines (with a vowel at the end). This came from the Latin word tufera, which was related to the word tuber, meaning "root", or today, "potato". Earlier back, though still in Latin, tuber meant a "swelling", and the former developed because it kind of looked like a bump out of the ground. It is by this logic that it makes sense that tuber came from Proto-Indo-European's word teue, "to swell" (the etymon of thumb, thousand, thigh, and tomb). If you look at the etymology of it, truffles aren't as gourmet as people make out.
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.