..I won't have to pester the demigods of the word world .
The illusion you're after is an absolute authority on the distinctive meaning of these two words - and on the meaning of words in general. And people here don't want to delude you into believeing that such an instance exists - they are proud to be anything you like except unanimous.

Freud wrote in German. There we have the word "Illusion", with a meaning very close to the English one. But there is no "Delusion" in German...