biscuit vs poker face

biscuit

noun
  • A small, flat, baked good which is either hard and crisp or else soft but firm; a cookie. 

  • The head. 

  • A puck (hockey puck). 

  • A form of unglazed earthenware. 

  • A thin oval wafer of wood or other material inserted into mating slots on pieces of material to be joined to provide gluing surface and strength in shear. 

  • A cracker. 

  • A plastic card bearing the codes for authorizing a nuclear attack. 

  • A handgun, especially a revolver. 

  • A small, usually soft and flaky bread, generally made with baking soda, which is similar in texture to a scone but which is usually not sweet. 

  • A light brown colour. 

  • The "bread" formerly supplied to naval ships, which was made with very little water, kneaded into flat cakes, and slowly baked, and which often became infested with weevils. 

poker face

noun
  • Any similar expression used to prevent giving away one's motives, feelings, or situation. 

  • An impassive facial expression cultivated to prevent other players from determining whether one's actions in the game are the result of a quality hand, or of bluffing. 

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