lightness vs roughness

lightness

noun
  • Levity, frivolity; inconsistency. 

  • The state of having little (or less) weight, or little force. 

  • the relative whiteness or transparency of a colour 

  • Agility of movement. 

  • The product of being illuminated. 

  • Freedom from worry. 

  • the condition of being illuminated 

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. 

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