sprocket vs whorl

sprocket

noun
  • A toothed wheel that enmeshes with a chain or other perforated band. 

  • The tooth of such a wheel. 

  • A placeholder name for an unnamed, unspecified, or hypothetical manufactured good or product. 

  • A flared extension at the base of a sloped roof. 

whorl

noun
  • A flywheel, a weight attached to a spindle. 

  • A circle of three or more leaves, flowers, or other organs, about the same part or joint of a stem. 

  • A volution, or turn, of the spire of a univalve shell. 

  • Any volution, as for example in the human ear or fingerprint. 

  • Each circle, volution or equivalent in a pattern of concentric circles, ovals, arcs, or a spiral. 

verb
  • To form a pattern of concentric circles. 

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