spinelessness vs vacillation

spinelessness

noun
  • The state or quality of being spineless (not having a spine (literally or figuratively)); cowardice. 

vacillation

noun
  • Indecision in speech or action. 

  • Changing location by moving back and forth. 

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