commander vs flagship

commander

noun
  • A naval officer whose rank is above that of a lieutenant commander and below that of captain. 

  • One who exercises control and direction of a military or naval organization. 

  • A designation or rank in certain non-military organizations such as NASA and various police forces. 

  • One who exercises control and direction over a group of persons. 

  • A rank within an honorary order: e.g. Commander of the Legion of Honour. 

  • Any of various nymphalid butterflies of the Asian genus Moduza. 

  • A heavy beetle or wooden mallet, used in paving, in sail lofts, etc. 

flagship

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

  • The most important one out of a related group. 

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

verb
  • To act as a flagship for. 

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