dead calm vs non-violent

dead calm

adj

  • Completely still with no waves and no wind. 

noun

  • The condition of a perfectly flat sea with no waves and no wind. 

non-violent

adj

  • Without violence. 

  • Sentenced for a crime that did not involve violence. 

  • Opposed to violence. 

How often have the words dead calm and non-violent occurred in a corpus of books? (source: Google Ngram Viewer )