--claim in the comments section of anything on the internet
"Fake news" means-- or at least SHOULD mean-- more than just a perspective you don't agree with or respect. According to dictionary.com, "Fake" means "designed to deceive or cheat; not real; counterfeit."
There is certainly plenty of that online, but there is far more news that isn't exactly fake but isn't exactly unbiased or thoroughly fact-checked, either.
Here's a great discussion of the "news ecosystem" and why we're fighting an "information war" every day: