dead calm vs unmitigated

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. 

unmitigated

adj

  • Total, complete, utter. 

  • Not mitigated. 

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