covert vs penfish

covert

noun
  • Area of thick undergrowth where animals hide. 

  • A covering. 

  • A disguise. 

  • A feather that covers the bases of flight feathers. 

  • A hiding place. 

adj
  • Under coverture. 

  • Secret, surreptitious, concealed. 

penfish

noun
  • Any of various porgies of the genus Calamus 

  • A squid. 

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