blather vs mussitate

blather

verb
  • To say (something foolish or nonsensical); to say (something) in a foolish or overly verbose way. 

  • To talk rapidly without making much sense. 

noun
  • Nonsensical or foolish talk. 

mussitate

verb
  • To say (words, etc.) indistinctly; to mutter. 

  • To talk indistinctly; to mutter. 

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