"Genius, throughout history, has been found difficult to classify because it varies in amount: It's rare to find a genius in the context of the noun, but most people, if not all, have a bit of genius in them in the context of the adjective."

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anything being perceived as being superior takes the noun. And everything that isn't, that's judged to be inferior, requires an adjective. So there are black novelists and novelists. There are women physicians and physicians. Male nurses and nurses.

— Gloria Steinem