cocoon vs obscure

cocoon

verb
  • To envelop in a protective case. 

  • To withdraw into such a 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. 

obscure

verb
  • To hide, put out of sight etc. 

  • To render obscure; to darken; to make dim; to keep in the dark; to hide; to make less visible, intelligible, legible, glorious, beautiful, or illustrious. 

adj
  • Dark, faint or indistinct. 

  • Difficult to understand. 

  • Not well-known. 

  • Hidden, out of sight or inconspicuous. 

  • Unknown or uncertain; unclear. 

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