emission

(n) the act of emitting; causing to flow forth emanation,
(n) a substance that is emitted or released discharge,
(n) the release of electrons from parent atoms
(n) any of several bodily processes by which substances go out of the body
- the discharge of pus
expelling, discharge,
(n) the occurrence of a flow of water (as from a pipe)

emanation discharge expelling

emission spectrum