serenity vs tenseness

serenity

noun
  • A lack of agitation or disturbance. 

  • The state of being serene; calmness; peacefulness. 

  • A title given to a reigning prince or similar dignitary. 

tenseness

noun
  • A particular vowel or consonant quality that is phonemically contrastive in many languages, including English. 

  • The characteristic of being tense. 

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