Of little weight or importance. (Merriam – Webster)
Behaving in a silly way and not taking anything seriously. (Cambridge Dictionary)
A frivolous activity or object is silly or not important rather than useful or serious. (Cambridge Dictionary)
Not having any serious purpose or value. (Oxford Dictionaries)
Fandom. I will not file frivolous lawsuits.
Frivolous Law and Legal Definition.
Frivolous, in general, means lacking in substance. In a legal context, frivolous claims are those which have no basis in fact or for which the law provides no remedy.