insubstantial vs trivial

insubstantial

adj
  • Lacking substance; not real or strong. 

trivial

adj
  • Ignorable; of little significance or value. 

  • Commonplace, ordinary. 

  • Pertaining to the trivium. 

  • Relating to or designating the name of a species; specific as opposed to generic. 

  • Self-evident. 

  • Concerned with or involving trivia. 

  • Of, relating to, or being the simplest possible case. 

  • Indistinguishable in case of truth or falsity. 

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