A multiple complainant—“multiple griever” is actually the terminology—would be someone who files multiple complaints or grievances. It could be 100; it could be 500.
Again, that's not the same as a vexatious complainant. A multiple griever is someone who files multiple complaints. Each and every one of those complaints could be a legitimate complaint and would be heard through the process.
The vexatious complainant is someone who is doing it not in good faith. It's a meritless complaint. It's frivolous in nature, and the intent of it...it's actually the content or the intent of the actual complaint.
I actually read through the definition of vexatious—I hope it was noted down by everyone around the committee—and that's really the terminology of the type of complaint.