outflow vs sluice

outflow

verb
  • To flow outward. 

noun
  • Any outward movement. 

  • Something that flows out of a sewage treatment plant. 

  • The process of flowing out. 

  • 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. 

sluice

verb
  • To flow, pour. 

  • To wash (down or out). 

  • To elide the complement in a coordinated wh-question. See sluicing. 

  • To emit by, or as by, flood gates. 

  • To wet copiously, as by opening a sluice 

  • To wash with, or in, a stream of water running through a sluice. 

noun
  • The stream flowing through a floodgate. 

  • A water gate or floodgate. 

  • A long box or trough through which water flows, used for washing auriferous earth. 

  • An instance of wh-stranding ellipsis, or sluicing. 

  • An artificial passage for water, fitted with a valve or gate, for example in a canal lock or a mill stream, for stopping or regulating the flow. 

  • Hence, an opening or channel through which anything flows; a source of supply. 

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