frivolous vs mordant

frivolous

adj
  • 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. 

  • Silly, especially at an inappropriate time or in an inappropriate manner. 

mordant

adj
  • Having or showing a sharp or critical quality 

  • Serving to fix a dye to a fibre. 

noun
  • A glutinous size used as a ground for gilding, to make the gold leaf adhere. 

  • Any substance used to facilitate the fixing of a dye to a fibre; usually a metallic compound which reacts with the dye using chelation. 

  • Any corrosive substance used in etching. 

verb
  • To subject to the action of, or imbue with, a mordant. 

How often have the words frivolous and mordant occurred in a corpus of books? (source: Google Ngram Viewer )