covert vs covert baron

covert

adj

  • Under coverture. 

  • Secret, surreptitious, concealed. 

noun

  • A covering. 

  • A disguise. 

  • A feather that covers the bases of flight feathers. 

  • Area of thick undergrowth where animals hide. 

  • A hiding place. 

covert baron

adj

  • Covert, under coverture; married. 

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