emission in WordNet English dictionary

1. any of several bodily processes by which substances go out of the body
   "the discharge of pus"
   discharge  emission  expelling 
   
2. a substance that is emitted or released
   discharge  emission 
   
3. the act of emitting; causing to flow forth
   emission  emanation 
   
4. the occurrence of a flow of water (as from a pipe)
   emission 
   
5. the release of electrons from parent atoms
   emission