Truthiness was coined by Stephen Colbert in 2005, and became legitimated as an entry in a dictionary by 2010.
> ... _truth_ just wasn’t “dumb enough.” “I wanted a silly word that would feel wrong in your mouth,” he said.
> What he was driving at wasn’t _truth_ anyway, but a mere approximation of it — something _truthish_ or _truthy_, unburdened by the factual. And so, in a flash of inspiration, _truthiness_, was born. [....]
> Five years later, _truthiness_ has proved to be no _bushlips_. It has even entered the latest edition of the New Oxford American Dictionary, published earlier this year, with Colbert explicitly credited in the etymology.
"Truthiness" | Ben Zimmer | The New York Times Magazine | October 13, 2010, cached at https://archive.is/lkEMX , original at https://www.nytimes.com/2010/10/17/magazine/17FOB-onlanguage-t.html