professor vs skill

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. 

skill

noun
  • Capacity to do something well; technique, ability. Skills are usually acquired or learned, as opposed to abilities, which are often thought of as innate. 

adj
  • Great, excellent. 

verb
  • To know; to understand. 

  • To have knowledge or comprehension; discern. 

  • To set apart; separate. 

  • To discern; have knowledge or understanding; to know how (to). 

  • To have personal or practical knowledge; be versed or practised; be expert or dextrous. 

  • To spend acquired points in exchange for skills. 

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