expulse vs flagpole

expulse

verb
  • To expel. 

flagpole

verb
  • Exit a country momentarily and reenter. Usually this is done to satisfy immigration requirements. 

noun
  • A tall pole up which one or more flags may be raised and flown. 

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