Vexatious litigation

Vexatious litigation is that which is brought, regardless of its merits (usually it has none) solely to harass or subdue an adversary. It may take the form of a primary frivolous lawsuit or may be the repetitive, burdensome and unwarranted filing of meritless motions in a matter which is otherwise a meritorious cause of action. It is an abuse of the judicial process and almost always brings down sanctions on the offender.

Repeated and severe instances by a single lawyer can result in his disbarment.

In some jurisdictions there is also a list of vexatious litigants, generally people who have repeatedly abused the legal system and who choose to represent themselves rather than employ a lawyer. Those on the list are in general forbidden from any further legal action. The process by which a person is added to the list varies between jurisdictions.