Would it help to know that it's just like leopardize, only with a 'j'? Or is that too silly? 'Course, now I wonder what sort of beast a jeopard would be. In Swedish and possibly German, it's a cheetah, only it's spelled with a 'g'. Which means, I suppose, that etymologists ought to consider the possibility that to jeopardize someone means putting them in front of a cheetah.