Saint Grobian (Medieval Latin, "Sanctus Grobianus") was a fictional patron saint of vulgar and coarse people. His name is derived from the Middle High German "grob" or "grop", meaning coarse or vulgar. The Old High German cognate is "gerob", "gerop". The word "grobian" has thus passed into the English language as an obscure word for any crude, sloppy, or buffoonish person. Wikipedia
The definitive Wikipedia entry for Grobian. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Grobian