dead on vs roughly

dead on

adj
  • very accurate 

adv
  • exactly at 

roughly

adv
  • Unevenly or irregularly. 

  • Without precision or exactness; imprecisely but close to in quantity or amount; approximately. 

  • In a rough manner; without kindness, softness, or gentleness. 

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