Discharge, emanation (8)
I believe the answer is:
emission
I believe this is a double definition.
'discharge' is the first definition.
(synonyms)
'emanation' is the second definition.
(synonyms)
(Other definitions for emission that I've seen before include "Something given out" , "radiation leakage?" , "The act of giving out (heat, light, gas, etc.)" , "Release" , "Sending forth" .)