I think it's a definition that has to emerge in consultation. The society comes up with it in consultation with the people who are being marginalized. If we think about how anti-Semitism is defined, some might argue that it's an imperfect term because Arabs are also Semites. Nevertheless, it has a particular definition. I'm not worried about finding the perfect term to describe an irrational fear of Muslims and Islam, a hyperbolic fear of Muslims and Islam. Usually when students come into my classes in the university, they do not know the difference between Islam and Muslim and how to use that correctly in a sentence. Usually it takes a few weeks for us to get to a place where they're able to do that in a literate way.
As I mentioned earlier, I don't think that people who are engaging in Islamophobic discourse can always tell the difference between Islam and Muslims or really worry about differentiating between them because the hate, as I said, is not very sophisticated.