>>98538777As a kid, I was told the reason we called native Americans Indians was because Columbus was looking for a passage to India, and, when he came across the Americas, he presumed that he had reached India and therefore, the people living where he found them would therefore be Indians. At that time, according to the oldest terrestrial globe we have, "india" referred to pretty much all of southeast asia.
What may have really happened I'm not entirely sure. That's the explanation I heard.