outfall vs outlet

outfall

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

  • A quarrel; a falling out. 

outlet

noun
  • A vent or similar passage to allow the escape of something. 

  • A river that runs out of a lake. 

  • Something which allows for the release of one's desires. 

  • A shop that sells the products of a particular manufacturer or supplier. 

  • A wall-mounted device such as a socket or receptacle connected to an electrical system at which current is taken to supply utilization equipment or appliances. 

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