What is the meaning of Frivolous?

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 whim or caprice.

Of little weight or importance; not worth notice; slight; trivial.

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.

Source: wiktionary.org