cocoon vs detach

cocoon

verb
  • To withdraw into such a case. 

  • To envelop in a protective case. 

noun
  • The silky protective case spun by the larvae of some insects in which they metamorphose, the pupa. 

  • Any similar protective case, whether real or metaphorical. 

detach

verb
  • To take apart from; to take off. 

  • To separate for a special object or use. 

  • To come off something. 

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