Can you tell me what is Truthiness?

That's a non-existent, made-up word. It was used in a public appearance

several years ago by a high-up political figure, who meant to say 'truthfullness'.

The word is used now to poke fun and derision at that public figure, or any other

equally pompous, clueless, or verbally challenged one.

Seeming truthful but without any evidence ...