Unium

Unium is an element that exists. However, you won't find it on the periodic table or the random table of ailments. That is because the scientific establishment denies it.

Unium got its name because it is not ium, the element that doesn't exist. How can an element that doesn't exist be an element? That doesn't make any sense at all!

In some Germanic languages, un means "not", and ium is a typical suffix for elements. So unium can be thought of as the not-element. This is fitting as it is not not.