An outlaw who punishes lawbreakers personally and illegally instead or relying on the inadequate law enforcers of society.
A vigilante could be either a robin hood-ish rescuer of the weak and destitute, a suspect-zero-ish killer of other killers, or a borderline insane killer of "bad people" (se7en).
They say Batman is nothing more than a vigilante. I say, what's so bad about that? Gotham's never felt so safe.
Individual who decides to take the law into his or her own hands. Usually due to incompetence by autority or individuals who can't deal with the issue.
A vigilante decided to kill the leaders of two dangerous gangs so the neighborhood is safer for children.
The one who will mend what has fallen apart when the laws of man have become obsolete with bloated bureaucracy and only serve the rich and powerful.
He used the ground and powdered bones of the rich as mortar for the bricks that built housing for the poor. What a vigilante.
lawlerstalker! in the trees!
Vigilante is such a stalker, did you see him in the trees with those binoculars?