clarification vs clear-out

clarification

noun
  • The act of freeing from obscurities. 

  • The act of clarifying; the act or process of making clear or transparent by freeing visible impurities; particularly, the clearing or fining of liquid substances from feculent matter by the separation of the insoluble particles which prevent the liquid from being transparent. 

clear-out

noun
  • The act of emptying a room or space. 

  • A semicircular sweep with the ball grasped firmly in both hands. 

How often have the words clarification and clear-out occurred in a corpus of books? (source: Google Ngram Viewer )