dead calm vs lifeless

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. 

lifeless

adj
  • inanimate; having no life 

  • dull or lacking vitality 

  • dead; having lost life 

  • uninhabited, or incapable of supporting life 

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