Earlier quoted context omitted.
Because lack of "prior art" is not a requirement for trademark, nor is uniqueness. "Coke" has other meanings http://en.wikipedia.org/wiki/Coke_(fuel) and yet is still trademarked.
That said, isn't it the case that one can't just take something that exists in common usage and trademark it as-is? For example, the basic structure of the fairy tale about Aladdin and the magic lamp had been around for a long time, and was clearly not originated by Disney. Consequently, Disney has no right to claim trademark or copyright control over the name Aladdin or or anything generally related to the story. Th…
No. You can totally do that as long as nobody has trademarked it in a similar context.