orifice vs outfall

orifice

noun
  • A mouth or aperture, such as of a tube, pipe, etc.; an opening. 

outfall

noun
  • The point or place of discharge of a river, drain, culvert, sewer, etc.; mouth; embouchure. 

  • A quarrel; a falling out. 

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