expelling vs refoulement

expelling

noun
  • The process by which something is expelled. 

refoulement

noun
  • Rendition of a person to an area (chiefly their country of origin) where they will face mistreatment, for example, expulsion of refugees into a war zone; (countable) an instance of this. 

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