musing vs rumination

musing

noun
  • thought, meditation, contemplation 

adj
  • Absorbed in thought; contemplative 

rumination

noun
  • Deep thought or consideration. 

  • The act of ruminating; i.e. chewing cud. 

  • Negative cyclic thinking; persistent and recurrent worrying or brooding. 

  • An eating disorder characterized by repetitive regurgitation of small amounts of food from the stomach. 

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