insignificant vs weighty

insignificant

adj
  • Not significant; not important, inconsequential, or having no noticeable effect. 

  • Without meaning; not signifying anything. 

weighty

adj
  • Important; serious; not trivial or petty. 

  • Rigorous; severe; afflictive. 

  • Heavy (“having a lot of weight”). 

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