flagpole vs follow up

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. 

follow up

verb
  • To take further actions remaining after an event; to continue, revisit, or persist; especially, to maintain communication or verify. 

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