I know that there are more than a few food writers who have ascribed the origin of the word pizza to the Italian word for point, which is indeed very similar: pizzo. The connection there is supposedly that pizza is cut into wedges, which are pointy on the ends. The problem I have with that idea is that pizzas in Italy tend to be smaller, about the size of a plate, and (at least these days) are eaten with a knife and fork, not sliced into wedges. The giant triangular slice o’ ‘za is an American invention, though even we don’t cut our pizza this way consistently (cutting pizza crosswise into squares instead of radially is a big Chicago thing where thin crust pizza is concerned, it’s also popular in St. Louis).
Another theory holds that pizzo is the ancestor to the Italian word pizzicare, which means to pinch or pluck, in the way that you “pluck” a pizza from an oven. This seems pretty darned far-fetched to me, and smacks of the same sort of national wishful thinking that has many Russians convinced that they invented baseball. The Russians also claim Kung Fu, the television, telephone and radio. I dunno, I guess you can’t blame a bunch of folks for trying.