frivolous

adjective3

1. •
   Silly, especially at an inappropriate time or in an inappropriate manner; lacking a good reason for being, or for doing what one does; due to or moved by a caprice or whim.
2. •
   Having no reasonable prospect of success because its claim is without merit, lacking a supporting legal or factual basis, while the filing party is, or should be, aware of this.

   • One of the major cost drivers in the delivery of health care are these junk and frivolous lawsuits. — 2005
3. •
   Of little weight or importance; not worth notice; slight; trivial.