It seems to too many people to mean this planet, a ball of rock in space. A globe is a picture of this EARTH, but not of our "world," right? If "world" can mean just one planet, this one, then that word does not properly translate "cosmos."
If it means as in "my world, and welcome to it"-- everything in our consciousness, our UNIVERSE, our KEN, then maybe cosmos could be translated 'world', but why bother?
Nearly every time it appears in NT, it is translating the Hebrew "olam" and its derivatives, which clearly imply other things in space, "olam" can even be a specific NON-earthly planet at times...
and normally refers to the infinite expanse of the eternal universe...