eldern vs senescent

eldern

adj
  • Elder; elderly; aged; old. 

  • Not new; old; ancient. 

senescent

adj
  • Characteristic of old age. 

  • That ceases to divide. 

  • Growing old; decaying with the lapse of time. 

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