casting vs propulsion

casting

noun
  • The act or process of selecting actors, singers, dancers, models, etc. 

  • Of hounds, the act of spreading out and searching for a scent. 

  • An object made in a mold. 

  • The regurgitation of fur, feathers, and other undigestible material by hawks, to clean and empty their crops.^([W]) 

  • The excreta of an earthworm or similar creature. 

  • A manufacturing process using a mold. 

  • The act of converting between data types. 

propulsion

noun
  • The action of driving or pushing, typically forward or onward; a propulsive force or impulse. 

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