mechanic vs serviceman

mechanic

noun
  • Someone who builds or repairs machinery, a technician; now specifically, someone who works with and repairs the mechanical parts of a motor vehicle, aircraft or similar. 

  • A cheat who manipulates the cards or dice. 

  • A manual worker; a labourer or artisan. 

  • A hitman. 

  • A device, command, or feature which allows someone to achieve a specific task. 

serviceman

noun
  • A person, especially a man, employed in service and maintenance of equipment. 

  • A man who serves in the armed forces. 

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