Quashed Squash

Occasionally, I'll hear of a court "quashing" something or other.  I'm not really sure what this means or how it happens, but it makes me chuckle a little.  It makes me think that the court would have preferred to "squash" it, but that didn't sound sophisticated enough so instead they decided to "quash".  If I liked cooked squash better, I think I'd try to come up with a squashed squash recipe, I think I'd need to use some type of bitter squash, and call it "quashed squash" and then invite some lawyers over to eat it.