It's an open question, certainly, but the broad meaning isn't vague. It's anything that would legally or technologically enable the Executive branch to disable

It's an open question, certainly, but the broad meaning isn't vague. It's anything that would legally or technologically enable the Executive branch to disable public internet access in all or part of the United States at will. I can't think up a way to make that a plausibly good thing to exist in any form.