assistant vs professor

assistant

adj
  • Helping; lending aid or support; auxiliary. 

  • Having a subordinate or auxiliary position. 

noun
  • A software tool that provides assistance in some task, a wizard program. 

  • Sales assistant. 

  • A person who assists or helps someone else. 

professor

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

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

  • A pianist in a saloon, brothel, etc. 

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

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