Linguasphere (it seems intuitively obvious, doesn’t it?) refers to that realm of existence composed entirely of language. It does this in the same way that "atmosphere" or "blogosphere" do for their constituent parts. Right now "linguasphere" is used as a technical term almost exclusively by a Quebecois linguistics outfit intent on cataloguing all the world’s languages (The Linguasphere Observatory), but its usefulness is hard not to appreciate. Linguasphere can also be used to describe the broad language realm of a particualar language, e.g., "the Italian linguasphere."
"So I framed the word in my mind and then released it into the linguasphere."
"People are getting so sloppy about what they say that it's time we cleaned up the linguasphere."
"That word floats high in the the English linguasphere."