Government of Canada "Bullying"

 Bullying is characterized by acts of intentional harm, repeated over-time, in a relationship where an imbalance of power exists. It includes physical actions (punching, kicking, biting), verbal actions (threats, name calling, insults, racial or sexual comments), and social exclusion (spreading rumours, ignoring, gossiping, excluding) (Pepler & Craig, 2000; Ma, Stewin & Mah, 2001).
  Boys tend to be more likely to bully and be bullied, usually in the form of a physical attack and exhibition of aggressive behaviour. Alternatively, girls appear to be more prone to indirect bullying in the form of social isolation, slandering and the spreading of rumours (Marcel T. Van der Wal, et al., 2003).

http://www.publicsafety.gc.ca/res/cp/res/2008-bp-01-eng.aspx