chairman vs flagship

chairman

verb
  • To serve as chairman. 

noun
  • The head of a corporate or governmental board of directors, a committee, or other formal entity. 

  • Someone whose job is to carry people in a portable chair, sedan chair, or similar conveyance. 

  • A person presiding over a meeting. 

flagship

verb
  • To act as a flagship for. 

noun
  • The most important one out of a related group. 

  • The ship occupied by the fleet's commander (usually an admiral); it denotes this by flying his flag. 

  • The ship regarded as most important out of a group, e.g. a nation's navy or company's fleet. 

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