Ok, sorry if I introduced a red herring by saying Scandinavian - I'm sure someone once told me this, but it now looks like rubbish. I still don't think it sounds very Irish, and am more inclined to believe that (as some say, above) it's originally Scottish,possibly taken up by Irish players later. This could mean there was a connection with Scandinavia, so maybe I wasn't so far out.

As to who "Ger" is and whether it's short for something, I have absolutely no idea.

Marje