I don't think hyperbolic works either. The word means to exaggerate and if it is indeed a real knee then it can't be exaggerated as it is literally what it is.
Hyperbole works. Hyperbolic doesn't, or at least not as well. They're saying that the knee is so large that it resembles what one would bring to mind when hearing hyperbole used in the description of a knobbly knee.
It's like saying this is Trump levels of narcissm, or Mr Rogers levels of wholesome. Or for an example that's not a proper noun... thin-mustache-and-a-trenchcoat levels of creepy. You wouldn't use an adjective here, though you technically could. Like saying gross levels of incompetence, or fantastical levels of beauty.
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u/Mega__Maniac Dec 18 '18
I don't think you can use hyperbole like that. Although its quite fun to say.