aging vs senescence

aging

noun
  • The process of becoming older or more mature. 

  • The accumulation of damage to macromolecules, cells, tissues and organs with the passage of time; the progressing loss of health, mobility, vibrancy and body functionality, resulting in biological death. 

  • The deliberate process of making something (such as an antique) appear (or, in science fiction, become) older than it is. 

  • Wear; wear and tear. 

adj
  • Becoming elderly. 

senescence

noun
  • The state or process of ageing, especially in humans; old age. 

  • Old age; accumulated damage to macromolecules, cells, tissues and organs with the passage of time. 

  • Fruit senescence, leading to ripening of fruit. 

  • Ceasing to divide by mitosis because of shortening of telomeres or excessive DNA damage. 

  • Condition when the cell ceases to divide. 

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