advisor vs aide

advisor

noun
  • One who offers advice. 

  • A xiangqi piece, that is moved one point diagonally and confined within the palace. 

aide

noun
  • An assistant. 

  • An officer who acts as assistant to a more senior one; an aide-de-camp. 

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