Factoid

Factoid is stating a fact that is not backed up by evidence. The factoid may not be trusted because
Factoids become widely treated as if they were true. 
In 1973, the term "factoid" was created and first used by Norman Mailer. 
A factoid is "an item of unreliable information which is repeated so often that it becomes accepted as a fact". The most important thing is that the factoid is widely believed. 
A factoid refers to something that looks like a fact, could be a fact, but in fact is not a fact.
The term can also be used to describe partial information without context.