Fake news is a type of hoax or deliberate spread of misinformation, be it via the traditional news media or via social media, with the intent to mislead in order to gain financially or politically from Wikipedia. Fake news can come from anyone and anywhere. Those well known for fake news include comedy television, extremists, politicians, social media, Internet forums, etc.
It can't be verified A fake news article may or may not have links in it tracing its sources; if it does, these links may not lead to articles outside of the site's domain or many not contain information pertinent to the article topic.
Fake news appeals to emotion: Fake news plays on your feelings - it makes you angry or happy or scared. This is to ensure you won't do anything as pesky as fact-checking.
Authors usually aren't experts: Most authors aren't even journalists, but paid trolls.
It can't be found anywhere else: If you look up the main idea of a fake news article, you might not find any other news outlet (real or not) reporting on the issue.
Fake news comes from fake sites: Did your article come from abcnews.co? or mercola.com? Realnewsrightnow.com? These and a host of other URLs are fake news sites.
Source: Wikimedia Commons
Fake News Watch - list of fake/hoax news websites, satire websites and clickbait websites
List of fake news websites from Wikipedia