roughness vs smoothness

roughness

noun
  • A measure of how rough something is, such as a surface 

  • Abundance, especially of food. 

  • Roughage; coarse fodder. 

  • The property of being rough, coarseness. 

  • Something that is rough; a rough spot. 

smoothness

noun
  • The quantity measured by the modulus of smoothness. 

  • The highest order of derivative (the differentiability class) over a given domain. 

  • The condition of being smooth; the degree or measure of said condition. 

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