The grandpa in question was half Sicilian and half French-Canadian, but Gaudioce strikes me as more French (and I know less than nothing about his Sicilian roots anyway; all the family names I've encountered in the photos seemed pretty damn French)... Judging by the photos, the French-Canadians hailed mostly from the Montreal area although they'd already had a southern New England presence as early as the 1890s.
Googling Gaudioce hasn't been very helpful, and French Wikipedia hasn't helped either. It doesn't seem to be much of a name...
Of course, though, alternate spellings of Gaudioce could exist that would render it quite a common name. I don't actually speak a word of French (or of Italian)... Spanish is the closest.
Husband's grandfather has been dead for over 10 years, and I'd never even met him, nor do I know any relatives who might know how/why the name Gaudioce came to be used in the family... (I suppose the fact that my husband and I eloped did limit my chances of meeting distant in-laws.)
So if anyone here has any ideas about the name Gaudioce, my idle curiosity will be eternally grateful!
EDIT: Just so that no one thinks I made Gaudioce up, here's a link to a scan of one of the old photos: http://www.flickr.com/photos/ice_weasel/2489461091/ And the photo suggests that this is already in Massachusetts. Gaudioce Rivard would've been the photographer's name, but maybe they took a photo of, say, their cousin? Or maybe they kept the photo because one of the subjects was someone they'd cared deeply about or something like that?