rubify vs rust

rubify

verb
  • to make red; to cause to redden 

  • to redden; to become red 

rust

verb
  • To cause to oxidize. 

  • To (cause to) degenerate in idleness; to make or become dull or impaired by inaction. 

  • To oxidize, especially of iron or steel. 

  • To be affected with the parasitic fungus called rust. 

  • Of a black cat or its fur, to turn rust-coloured following long periods of exposure to sunlight. 

noun
  • A similar substance based on another metal (usually with qualification, such as "copper rust"). 

  • A disease of plants caused by a reddish-brown fungus. 

  • Damage caused to stamps and album pages by a fungal infection. 

  • The deteriorated state of iron or steel as a result of moisture and oxidation. 

  • A reddish-brown color. 

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