Tonsure: part of a monk's head left bare on top by shaving off the hair. As in, "This tonsure is not only totally holy, they allow God to beam his thoughts directly into my head without the messy bother of hair getting in the way." Tonsure can also be used as a verb (like I did here!)
I think the main thing to take away here is that we finally have a word for "that goofy haircut that monks wear, you know, that sort of monk-y fringe? No? Anyone? What the hell is that called?" Now we know. Another fun fact: the practice of tonsure was not abandoned by the Catholic church until 1972. I guess they didn't want to hold out hope for tonsure fitting in any better as the late 70's and early 80's came on (not that the Pope keeps up with fashion, but I agree that was probably the right call).