What's the term/word for a legal case without merit?

What's the term/word for a legal case without merit?

There's something more technical than "fraudulent" or "groundless"... can't pinpoint it.

Here in the UK: "weak, frivolous and unmeritorious cases"; "totally without merit" (TWM):

What is the test the Court should apply in deciding whether an application is ‘totally without merit’? The question is prompted by the Lord Chancellor’s announcement on 23 April 2013 that he will press ahead with plans to reform judicial review procedure to target ‘weak, frivolous and unmeritorious cases’.

A key change will be to give judges of the Administrative Court, when refusing permission to apply for judicial review on the papers, the power to certify a claim as ‘totally without merit’ (TWM), thus depriving the claimant of the right to renew the application before the court at an oral hearing.

Judicial Review reform: What does “totally without merit” mean? – Paul Bowen QC

See also frivolous litigation:

Frivolous litigation may be based on absurd legal theories, may involve a superabundance or repetition of motions or additional suits, may be uncivil or harassing to the court, or may claim extreme remedies. A claim or defense may be frivolous because it had no underlying justification in fact, or because it was not presented with an argument for a reasonable extension or reinterpretation of the law. A claim may be deemed frivolous because existing laws unequivocally prohibit such a claim

Perhaps also a vexatious proceeding:

The characteristics of ‘vexatious conduct’ set out by Lord Bingham were as follows:

“The hallmark of a vexatious proceeding is in my judgment that it has little or no basis in law (or at least no discernible basis); that whatever the intention of the proceeding may be, its effect is to subject the defendant to inconvenience, harassment and expense out of all proportion to any gain likely to accrue to the claimant; and that it involves an abuse of the process of the court, meaning by that a use of the court process for a purpose or in a way which is significantly different from the ordinary and proper use of the court process.”

Vexatious litigation:

Vexatious litigation is legal action which is brought, regardless of its merits, 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. Filing vexatious litigation is considered an abuse of the judicial process and may result in sanctions against the offender.

If their behaviour is querulous, the person filing the case is a querulant:

Querulous (from the Latin for plaintive murmuring) is used in this article to describe a pattern of behaviour involving the unusually persistent pursuit of a personal grievance in a manner seriously damaging to the individual’s economic, social, and personal interests, and disruptive to the functioning of the courts and/or other agencies attempting to resolve the claims. Potentially included among the querulous are three broad types, unusually persistent complainants, vexatious litigants, and those who in pursuit of idiosyncratic quests harass the powerful and prominent with petitions and pleas. Excluded from this category are social reformers and campaigners who use litigation and complaint to advance agendas of potential public interest, even if they are pursuing unpopular causes in a disruptive manner.

Vexatious Litigants and Unusually Persistent Complainants and Petitioners: From Querulous Paranoia to Querulous Behaviour
Paul E. Mullen and Grant Lester
Behavioral Sciences and the Law
Behav. Sci. Law 24: 333–349 (2006)
Published online 16 May 2006 in Wiley InterScience
(www.interscience.wiley.com). DOI: 10.1002/bsl.671

A barrator

One who vexatiously raises, or incites to, litigation; a mover or maintainer of law-suits; one who from maliciousness, or for the sake of gain, raises discord between neighbours.

commits barratry:

The offence of habitually exciting quarrels, or moving or maintaining law-suits; vexatious persistence in, or incitement to, litigation.

The following table (from Mullen/Lester cited above) is quite revealing. This form of communication will probably be familiar to anyone who has used the Internet for a while.

Table 1. Anomalies found frequently in written communications from the querulous

Form

• Curious formatting.
  
• Many, many pages.
  
• Odd or irrelevant attachments—e.g., copies of letters from others and legal decisions, UN Charter on Human Rights etc., all usually, extensively annotated.
  
• Multiple methods of emphasis including highlighting (various colours), underlining, capitalization.
  
• Repeated use of ‘‘’’, ???, !!!.
  
• Numerous foot and marginal notes.
  

Content

• Rambling discourse characterized by repetition and a pedantic failure to clarify.
  
• Rhetorical questions.
  
• Repeated misuse of legal, medical and other technical terms.
  
• Referring to self in the third person.
  
• Inappropriately ingratiating statements.
  
• Ultimatums.
  
• Threats of violence to self or others.
  
• Threats of violence directed at individuals or organizations.
  

As a psychiatric condition this is 'querulous paranoia':

This language dates back to the Victorian era, was written about by the seminal German psychiatrist Emile KRAEPELIN and has been written about in psychiatric journals. Querulous, or querulent, paranoia is usually defined as the propensity to make persistent complaints about comparatively trivial issues, sometimes where there is no foundation to the complaint(s); and to pursue those grievances to the point where the damage done to oneself from the process and any dissatisfaction with the outcome is even greater than the original issue. And possibly, to then further complain about the inaction to the original complaint or dissatisfaction with its outcome. ...

The literature distinguishes this condition of querulous paranoia from the relentless pursuit of redress after serious injustice.

History of the term (re-popularised by the paper cited here):

The querulant and the paranoid litigant once occupied a privileged position among psychiatric disorders ... Such people were regarded as inhabiting the borderline between delusional psychosis and the fanatical preoccupations of the psychopathic personalities ... Clérambault (1942) included them in his ‘psychoses passionelles’, and they found their way into both the ICD and DSM classificatory systems ... Although occasional studies of vexatious litigants continue to appear ..., the category fell into disrepute, undermined by criticisms that it was doing no more than pathologising those with the energy and commitment to pursue their rights ... Querulousness retreated into obscurity just as complaint was coming to occupy a central position in maintaining the social compact in Western culture ... The querulous, given the current neglect of this category, now pass largely unrecognised and unregarded by mental health professionals ...

Complaints organisations and the courts continue to be plagued by a small group of unusually persistent people who consume enormous amounts of resources. This study addressed the nature of this group, whether its members resembled those described in the old literature on querulousness, and if there was evidence that the way in which their claims had been dealt with initially had launched them on this disastrous course.

Unusually persistent complainants
Grant Lester et al
The British Journal of Psychiatry (2004) 184: 352-356
doi: 10.1192/bjp.184.4.352

Of course one must be careful in throwing around accusations of 'querulous paranoia' - one could unfairly pathologise people with a legitimate complaint. This is why mental health professionals have, until recently, backed off from use of the term. But it may be making a comeback:

Mental health professionals have, over recent decades, stepped back from involvement with those once viewed as querulous – or have been pushed back. There are good reasons for caution in introducing concepts of personal pathology into social processes such as complaining, but equally it is cavalier to ignore the possibility that knowledge and approaches developed in the mental health field might offer help to organisations and individuals in avoiding the damaging and distressing effects of unusually persistent complaining. Perhaps it is time to restore querulousness to a legitimate place among the problem behaviours that mental health professionals study and manage.

(ibid.)