insatiable vs unappeased

insatiable

adj
  • Not satiable; incapable of being satisfied or appeased; very greedy 

noun
  • One who or that which cannot be satiated. 

unappeased

adj
  • That has not been appeased 

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