sad vs tough

sad

adj
  • Appearing sorrowful. 

  • Soggy (to refer to pastries). 

  • Causing sorrow; lamentable. 

  • Of colours: dark, deep; later, sombre, dull. 

  • Feeling sorrow; sorrowful, mournful. 

  • Poor in quality, bad; shameful, deplorable; later, regrettable, poor. 

  • Unfashionable; socially inadequate or undesirable. 

tough

adj
  • Harsh or severe. 

  • Difficult or demanding. 

  • Stubborn or persistent; capable of stubbornness or persistence. 

  • Strong and resilient; sturdy. 

  • Undergoing plastic deformation before breaking. 

  • Difficult to cut or chew. 

  • Rugged or physically hardy. 

  • Rowdy or rough. 

intj
  • Used to indicate lack of sympathy 

noun
  • A person who obtains things by force; a thug or bully. 

verb
  • To endure. 

  • To toughen. 

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