mopping vs washing

mopping

noun
  • An application of molten asphalt to a roof etc. 

  • The process of cleaning with a mop. 

washing

noun
  • A place where a precious metal found in gravel is separated from lighter material by washing. 

  • A fraudulent transaction in which the same stock is simultaneously bought and sold for the purpose of manipulating the market. 

  • The covering of a piece with an infusible powder, which prevents it from sticking to its supports, while receiving the glaze. 

  • A thin covering or coat. 

  • The action of the verb to wash 

  • My mother used to do the washing on a Monday 

  • Clothing, bedlinen or soft furnishings that have been, are currently being, or are to be washed; laundry. 

  • The residue after an ore, etc, has been washed 

  • The liquid used to wash an ore. 

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