hey TEd, will an answer from a Canuck (who is deeply in touch with her British roots) do?!

My understanding of "jammy" is that it means "lucky," prolly because Brits do love their jam, though I'm willing to sit corrected if I'm wrong. A git is an annoying person. "Jammy" has, I believe, an additional connotation, in that someone who is jammy got lucky without really trying.

Now let's see what t'other side o' t'pond has ter say....