outgrowth vs parentage

outgrowth

noun
  • A byproduct or consequence of an action or event. 

  • An appendage of an animal. 

  • A branch or offshoot of a plant. 

  • Excessive growth. 

parentage

noun
  • Origin; derivation. 

  • The social quality of one's class in society. 

  • The identity and nature of one's parents, and in particular, the legitimacy of one's birth. 

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