The term is Worshipfull Master and as apparently your grandfather never told you, the Worshipfull Master, is the leader of the lodge for that year.
I did a little research last year and found out that actually Catholics, even Popes used to be quite active in the lodge in ages past. It would seem that a falling out occured with one of the Popes years ago and he then issued an edict that no Catholic could join the Masons.
The Masons and their affiliate bodies, the Scottish Rite, York Rite, and the Shriners do many good deeds for the community, and are by no means nor do we pretend to be any sort of religion. Not at the first degree level or at any level of Free Masonry.
But you can't tell that to the odd assortment of Catholics and born again fundamentalists that come in this forum and attack the Masons on threads like this one.
If you are the "Worshipful Master" what do you worship?? Don't tell me that it's just a "title"....words DO mean things.