the quality of stating concepts one wishes or believes to be true, rather than the facts.
Michael Adams, a professor at North Carolina State University who specializes in lexicology, said "truthiness" means "truthy, not facty."
"The national argument right now is, one, who's got the truth and, two, who's got the facts," he said. "Until we can manage to get the two of them back together again, we're not going make much progress."
If anyone else is confused by this word usage (truth vs. facts), I would like to remind you there are reasons scientists have their own vocabulary.