lastborn vs progeniture

lastborn

noun
  • The youngest child of a family. 

  • The youngest member of any company or organization. 

adj
  • Born last in a family; youngest in a the family. 

  • Younger than anyone else in a group. 

progeniture

noun
  • offspring, progeny 

  • ancestry, lineage 

  • procreation 

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