spoor vs stepping

spoor

noun
  • The track, trail, droppings or scent of an animal. 

verb
  • To track an animal by following its spoor 

stepping

noun
  • The act of taking a step. 

  • A specific iteration of a model of central processing unit, often distinguished by the addition or removal of features compared to earlier examples of the same processor, or the presence, or lack thereof, of specific bugs. 

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