alert vs senescent

alert

verb
  • To give warning to. 

noun
  • An alarm. 

  • A state of readiness for potential combat. 

  • A notification of higher importance than an advisory. 

adj
  • Attentive; awake; on guard. 

senescent

adj
  • Characteristic of old age. 

  • That ceases to divide. 

  • Growing old; decaying with the lapse of time. 

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