When Christopher Columbus discovered the Americas, he came across the Carib people. However, when they introduced themselves, he misinterpreted their name as the Caniba. Eventually this was corrected, but it was too little, too late: Columbus' error lasted long enough to seep into another language. It was picked up by the Spanish as the word canibal, meaning "one who eats other humans", because of false stereotypes by the Europeans. This became our word cannibal later on as well. Interestingly, the name for the region, the Caribbean, comes from the correct spelling of the native name, so human-eaters and the sea below Florida are etymologically connected. Cannibal showed up as a word almost two centuries before Caribbean did, which says a lot.
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.