bidding vs discretionary

bidding

noun
  • That which one is bidden to do; a command. 

  • The act of placing a bid. 

discretionary

adj
  • Available at one's discretion; able to be used as one chooses; left to or regulated by one's own discretion or judgment. 

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