Someone who is disliked and rejected by other people: Mildred was a talented player, but her angry outbursts made her a pariah in the sport of tennis.

Any of several tropical South American freshwater fish that are voraciously carnivorous and often attack and destroy living animals: Fred and Eugenia could see the multitudes of piranha attacking the small deer in the river with their sharp teeth and strong jaws and quickly devouring the animal.

Bryan is considered a piranha in the insurance business because he "eats" up the competition.