degeneration vs dry rot

degeneration

noun
  • A thing that has degenerated. 

  • The process or state of growing worse, or the state of having become worse. 

  • That condition of a tissue or an organ in which its vitality has become either diminished or perverted; a substitution of a lower for a higher form of structure. 

  • Gradual deterioration, from natural causes, of any class of animals or plants or any particular organ or organs; hereditary degradation of type. 

dry rot

noun
  • Any progression of decay, corruption, or obsolescence. 

  • The crumbly, friable decayed portions of wooden members of buildings, especially at or below grade, usually caused by a fungal infection. 

  • A fungal infection which affects plants, in particular potatoes. 

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