aeruginous vs rusty

aeruginous

adj
  • Of or pertaining to copper-rust or verdigris. 

rusty

adj
  • Marked or corroded by rust. 

  • Affected with the fungal plant disease called rust. 

  • Of clothing, especially dark clothing: worn, shabby. 

  • Discolored and rancid; reasty. 

  • Lacking recent experience, out of practice, especially with respect to a skill or activity. 

  • Of the rust color, reddish or reddish-brown. 

noun
  • A gun or in particular an old or worn one. 

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