A person who is a specialist in the studies of hating. Full blown haters can see haterologists to find the true reason they are haters. They can express their hatelems in haterology sessions and try to live hater free with the help of a haterologists.
Popo is a big hater, he's always hating on Botz, Eddie, Ratt, & Timo. He should go see Manny, the haterologist, and get some help for his hateritis.