offshoot vs outgrowth

offshoot

noun
  • That which shoots off or separates from a main stem or branch of a plant. 

  • That which develops from something else. 

outgrowth

noun
  • A branch or offshoot of a plant. 

  • An appendage of an animal. 

  • Excessive growth. 

  • A byproduct or consequence of an action or event. 

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