simple vs tough

simple

adj
  • Feeble-minded; foolish. 

  • Consisting of a single individual or zooid; not compound. 

  • Consisting of one single substance; uncompounded. 

  • Undistinguished in social condition; of no special rank. 

  • Without ornamentation; plain. 

  • Free from duplicity; guileless, innocent, straightforward. 

  • Of a group: having no normal subgroup. 

  • Homogenous. 

  • Using steam only once in its cylinders, in contrast to a compound engine, where steam is used more than once in high-pressure and low-pressure cylinders. 

  • Not compound, but possibly lobed. 

  • Uncomplicated; taken by itself, with nothing added. 

noun
  • Part of the apparatus for raising the heddles of a drawloom. 

  • A herbal preparation made from one plant, as opposed to something made from more than one plant. 

  • A feast which is not a double or a semidouble. 

  • A drawloom. 

  • A simple or atomic proposition. 

tough

adj
  • Stubborn or persistent; capable of stubbornness or persistence. 

  • Harsh or severe. 

  • Difficult or demanding. 

  • 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 

verb
  • To endure. 

  • To toughen. 

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

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