A person of little, if any intelligence or general importance in society. A person who can be easily bullied or victimised for either a) their accent or b) their general incompetence. A Brummie is a person who improves the lives of those around them, but only because they will fall up a stair and yell out loudly in pain, therefore adding to the hilarity of any situation.
That kid just fell down while standing still. He must be a Brummie