locomotive vs locomotor

locomotive

adj
  • Of or relating to locomotion. 

  • Of or relating to the power unit of a train which does not carry passengers or freight itself. 

noun
  • The power unit of a train that pulls the coaches or wagons. 

  • A country which drives the world economy by having a high level of imports, such as the United States. 

  • A cheer characterized by a slow beginning and a progressive increase in speed. 

  • A traction engine. 

locomotor

adj
  • Of or pertaining to movement or locomotion. 

noun
  • Something that is capable of locomotion. 

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