senator vs speaker

senator

noun
  • A member, normally elected, in the house or chamber of a legislature called a senate, as, for instance, the legislatures of the United States and Canada. 

  • A member of the ruler’s council or governing council in general, a leading statesman. 

  • A member of the ancient Roman Senate. 

  • A member of a governing council in other states in the ancient world. 

speaker

noun
  • The chair or presiding officer of certain legislative bodies, such as the U.K. House of Commons or the U.S. House of Representatives. 

  • Speakerphone. 

  • The literary character uttering the lyrics of a poem or song, as opposed to the author writing the words of that character. 

  • The producer of a given utterance, whether speech or text. 

  • A book containing passages of text for use in speeches. 

  • A key on a woodwind instrument of the clarinet family (cf octave key on other instruments) which induces the instrument to overblow. 

  • One who makes a speech to an audience. 

  • One who speaks. 

  • Loudspeaker. 

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