1. The experience of mental exhaustion which often follows a long period of reading, writing, or talking about philosophy, and perhaps having one's mind blown by the conclusions.
2. A state of mind in which one's mental resources are completely spent as a result of excessive philosophizing and therefore good philosophy is no longer possible (i.e. the refractory period between philosophical thoughts or discussions).
"I wrote that paper on Kant for five hours straight and now I'm completely philosofizzled. I need a nap."
"Let's continue this conversation later. We're not making sense anymore; we must be philosofizzled."