airfoil vs pinion

airfoil

noun
  • A wing of an aircraft. 

  • A structure shaped to produce lift when moving in air. 

pinion

noun
  • A wing. 

  • The smallest gear in a gear train. 

  • Any of the outermost primary feathers on a bird's wing. 

  • A moth of the genus Lithophane. 

  • The joint of a bird's wing farthest from the body. 

verb
  • To restrain; to limit. 

  • To cut off the pinion of a bird’s wing, or otherwise disable or bind its wings, in order to prevent it from flying. 

  • To bind the arms of someone, so as to deprive him of their use; to disable by so binding. 

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