professor vs trainer

professor

noun
  • A teacher or faculty member at a college or university regardless of formal rank. 

  • The most senior rank for an academic at a university or similar institution, informally also known as "full professor." 

  • A pianist in a saloon, brothel, etc. 

  • The puppeteer who performs a Punch and Judy show; a Punchman. 

trainer

noun
  • A person who trains another; a coach. 

  • A person responsible for treating injuries sustained by players during matches; a physiotherapist. 

  • A patch for a video game that applies cheats. 

  • A running shoe or sneaker. 

  • A piece of indoor equipment allowing a bicycle to be ridden while stationary. 

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