dotage vs senescence

dotage

noun
  • Decline in judgment and other cognitive functions, associated with aging; senility. 

  • Fondness or attentiveness, especially to an excessive degree. 

  • Foolish utterance(s); drivel. 

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 dotage and senescence occurred in a corpus of books? (source: Google Ngram Viewer )