arbor vs axle

arbor

noun
  • A spindle of a wheel. 

  • A shady sitting place or pergola usually in a park or garden, surrounded by climbing shrubs, vines or other vegetation. 

  • A grove of trees. 

  • A bar for supporting cutting tools. 

  • An axis or shaft supporting a rotating part on a lathe. 

axle

noun
  • The pin or spindle on which a wheel revolves, or which revolves with a wheel. 

  • A transverse bar or shaft connecting the opposite wheels of a car or carriage; an axletree. 

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