My days of decent knowledge of Latin are a little in the past since I passed my Latinum, and I am trying to get a good translation for what modern US courts call "vexatious litigant" into Latin for a little joke to a lawyer friend of mine - because illnesses have often Latin names and there's a lot of law-Latin around, just not the "vexatious litigant". I was planning to use this construction in combination with the imperative of abstain for the goal of "keep away the vexatious litigant".
The best translation for the word vexatious I could find is the root of it: vexatio, vexationis in its 4th meaning of "trouble, vexation".
Now Litigant also has a fitting Latin stem in litigere, litigo, in its 2nd meaning "to litigate/sue".
But here I get to the end of my Latin: How to properly combine the two to get the vexatious litigant?