mumble vs spraff

mumble

verb
  • To speak unintelligibly or inaudibly; to fail to articulate. 

  • To chew something gently with closed lips. 

noun
  • A quiet or unintelligible vocalization; a low tone of voice. 

spraff

verb
  • To speak excessively or pointlessly. 

  • To speak (in general). 

noun
  • Spiel. 

  • Chat, patter. 

  • Speech. 

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