outflow

Short definition from Wiktionary

Noun

1. 1
   The process of flowing out.
2. 2
   A fluid that flows out.
3. 3
   Any outward movement.
4. 4
   A stream of gaseous material emanating from an active galactic nucleus.
5. 5
   The part of a system that allows material to flow out.
6. 6
   Something that flows out of a sewage treatment plant.

Verb

1. 1
   To flow outward.