A verb. When someone is given wrong factual information but doesn't bother checking if it's correct and goes on telling everyone about it, making himself look like an idiot. We say he was fact. Such wrong information is usually given by a person that was fact and doesn't know it, or is ignorant on purpose.

The place most people in the world tend to think their opinions reside...

That which is founded in truth.

Making a statement, whether true or not, and finishing off with the word 'fact' in capital letters, so to add emphasis and complete authority.

When somebody adds "Fact" to the end of their sentence, they are usually stating a controversial opinion, as if the addition of the word makes it so just because they said so.

Usually it is a sign of unwarranted self-importance.

1) Good way to make yourself look pretty damn cool at the same time as adding no weight whatsoever behind the obviously controversial statement that you have just made.

2)The Federation Against Copyright Theft (FACT) - the big FACT symbol you see during the trailers when you go to the cinema.

# a piece of information about circumstances that exist or events that have occurred; "first you must collect all the facts of the case"
# a statement or assertion of verified information about something that is the case or has happened; "he supported his argument with an impressive array of facts"
# an event known to have happened or something known to have existed; "your fears have no basis in fact"; "how much of the story is fact and how much fiction is hard to tell"
# a concept whose truth can be proved; "scientific hypotheses are not facts"

see taint as its the best answer to what a fact is