lastborn vs offspring

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. 

offspring

noun
  • A person's daughter(s) and/or son(s); a person's children. 

  • All of a person's descendants, including further generations. 

  • An animal or plant's progeny or young. 

  • Anything produced; the result of an entity's efforts. 

  • A process launched by another process. 

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