nothingness vs unimportance

nothingness

noun
  • The quality of inconsequentiality; the lack of significance. 

  • A void; an emptiness. 

  • The state of nonexistence; the condition of being nothing. 

unimportance

noun
  • Lack of importance. 

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