Meaning homozygous spider (AKA "super spider" in snake parlance).
I was going to write out an explanation for what that means, but then I remembered that JLC has this very nice synopsis all typed out here:
http://ball-pythons.net/forums/showt...Basic-Genetics
Basically, the theoretical spider with two copies of the gene got one from each parent, one from the sire and one from the dam.