Goyness is a term/phrase used to explain how much
influence 'Goy' or 'Goys' have on
something, a Goy is a term that people of the Jewish/Judaist faith have adopted for 'Infidels' or 'Nonbelievers' making the word 'Goy' a placeholder value for that.
Goyness is how much Goy is in
something.