carefree vs dead calm

carefree

adj

  • Without cares or worries; free of concern or worries; without difficulty. 

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. 

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