No lack of seriousness intended, truly. The word evidence has special meaning for science, correct? ringo made a flat statement that any idea that is not supported by evidence is fanciful by definition, The word she referenced for definition was fanciful. I looked fanciful up in Merriam-Webster and found no reference to evidence in any of the accepted definitions. My suggestion is perhaps she should find a better word.
Well, after a few minutes with a thesaurus, how about baseless, conjectural, groundless, hypothetical, imaginary, notional, speculative, suppositional, unconfirmed, uncorroborated, unestablished, unevidenced, unfounded, unjustifiable, unproven, unsubstantiated, unsupported, unverified, or up in the air?