conceal vs extrude

conceal

verb
  • To hide something from view or from public knowledge, to try to keep something secret. 

extrude

verb
  • To push or thrust out. 

  • To expel; to drive off. 

  • To form or shape (a metal, plastic etc.) by forcing it through a die or an opening. 

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