it refers to a person who has the habit of picking-on to those people around especially to those slow or weak ones. it's an act wherein the doer threatens or who demands arrogantly. it can also be a term used to define a person who has joyous humor , who has full of joy and happiness . it's like watching any live sports or contest and everyone is making a bully to encourage your favorite team and at the same time bully the team you don't like to destruct that team's attention.