expelling vs emission

expelling and emission both are nouns.

Word	Noun	Adjective	Verb	Adverb
expelling	Yes	No	No	No
emission	Yes	No	No	No

As nouns, expelling and emission are synonyms defined as:

expelling and emission: any of several bodily processes by which substances go out of the body

Other synonyms of expelling include discharge.

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