Used to refer to an unknown disease, most commonly a disease of the sexually transmitted variety.
Carmine: Did you see that chick Sylvester took home last night?
Dude: Yeah she was sketchy, he probably caught the flajaundice.
Carmine: He should get that checked.
Ricky: Does this look like syphilis to you?
Steve: I don't know but it's flajaundice for sure.
Ricky: I should get that checked.