The Collaborative International Dictionary of English v.0.48:
Emission \E*mis"sion\, n. [L. emissio: cf. F. ['e]mission. See
1. The act of sending or throwing out; the act of sending
forth or putting into circulation; issue; as, the emission
of light from the sun; the emission of heat from a fire;
the emission of bank notes.
2. That which is sent out, issued, or put in circulation at
one time; issue; as, the emission was mostly blood.
Emission theory (Physics), the theory of Newton, regarding
light as consisting of emitted particles or corpuscles.
See Corpuscular theory, under Corpuscular.