dead calm vs sleepy

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. 

sleepy

adj
  • Quiet; without bustle or activity. 

  • Tending to induce sleep. 

  • Tired; feeling the need for sleep. 

  • Suggesting tiredness. 

  • Dull; lazy. 

noun
  • The gum that builds up in the eye; sleep, gound. 

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