ironing vs washwater

ironing

noun
  • Laundry that has been washed and is ready to be ironed. 

  • The act of pressing clothes with an iron. 

  • Laundry that has recently been ironed. 

washwater

noun
  • Water used for washing, especially in industrial processes. 

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