concurrence vs strife

concurrence

noun
  • Agreement; concurring. 

  • An instance of simultaneous occurrence. 

strife

noun
  • Striving; earnest endeavor; hard work. 

  • A trouble of any kind. 

  • Bitter conflict, sometimes violent. 

  • Exertion or contention for superiority, either by physical or intellectual means. 

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