1st definition: The supporting of proven false information as factual regardless of evidence or reality.

2nd definition(slang): Delusional thinking, undeterred by fact, convinced that the lies of themselves or others are true.

3rd definition (group): Those who support such delusional or non-factual thinking.
The president of an unnamed country believes an alt-truth media outlet like InfoWars offers actual facts.
by 111111WWWWXmkdv'zdi'hgb April 8, 2017
Get the Alt-truth mug.