seeker vs whistle-stopper

seeker

noun
  • In the sport of Quidditch or Muggle quidditch, a player who attempts to catch the snitch. 

  • One who seeks. 

  • Especially, a religious seeker: a pilgrim, or one who aspires to enlightenment or salvation. 

whistle-stopper

How often have the words seeker and whistle-stopper occurred in a corpus of books? (source: Google Ngram Viewer )