It means that the snake is Heterogeneous for the ghost gene. It is a biology term used to when someone or something may be carrying a particular gene in their genotype. We (and snakes) have a genotype and a phenotype. Your phenotype is what you look like your genotype is what your genes are made up off. Let's say you for example have brown eyes, but you are carrying the gene for blue eyes. That would mean that your phenotype is brown eye colour but your genotype has both genes in it. So that would make you het for blue eyes.
Back to snakes. If you pair an albino (which is a simple recessive trait) with a normal coloured snakes (normal colours are dominant colours) you will get snakes that look normal but are all carrying the albino gene so we say that they are 100% het for albino. Pair an albino with a 100% het and you'll get a litter or clutch that is half and half.
Hope this helped,
Trevor
PS
Corey nice snake man!