expound vs spiel

expound

verb
  • To make a statement, especially at length. 

  • To set out the meaning of; to explain or discuss at length 

spiel

verb
  • To talk at length. 

  • To give a sales pitch; to promote by speaking. 

noun
  • A game of curling. 

  • A lengthy and extravagant speech or argument usually intended to persuade. 

  • An early form of rap music. 

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