outflow vs spillage

outflow

noun
  • The process of flowing out. 

  • Any outward movement. 

  • Something that flows out of a sewage treatment plant. 

  • A fluid that flows out. 

  • A stream of gaseous material emanating from an active galactic nucleus. 

  • The part of a system that allows material to flow out. 

verb
  • To flow outward. 

spillage

noun
  • The process or action of spilling. 

  • That which has been spilled. 

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