covert vs shrouded

covert

adj
  • Secret, surreptitious, concealed. 

  • Under coverture. 

noun
  • A covering. 

  • A disguise. 

  • A feather that covers the bases of flight feathers. 

  • Area of thick undergrowth where animals hide. 

  • A hiding place. 

shrouded

adj
  • Concealed or hidden from sight, as if by a shroud. 

  • Wearing, or provided with a shroud. 

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