It is important to distinguish between rude, mean and bullying so that teachers, school administrators, police, youth workers, parents and kids all know what to pay attention to and when to intervene. As we have heard too often in the news, a child's life may depend on a non-jaded adult's ability to discern between rudeness at the bus stop and life-altering bullying.
When parents allow themselves to get distracted by surface misbehavior, they push their children away at just the time that the young person needs to be held most closely. In the heat of the moment, don't take anything your child says personally but do remember how desperately she needs your love and support at this time in her life.
When a kid, or a nation, or a community of nations, is terrorized by a bully who acts with unconcealed confidence that no one will challenge him or intervene on behalf of his victims, it is up to each kid, each nation, each community of nations, to stop being afraid and act quickly, powerfully, and decisively.
I think the word bullying is overused in general -- with both adults and minors. We see the word being used inappropriately or out of context in many cases today... I think society has co-opted this term, which is sad, because it is actually weakening it and people are not taking it serious as they should.