excretion vs evacuation

excretion and evacuation both are nouns.

Word	Noun	Adjective	Verb	Adverb
excretion	Yes	No	No	No
evacuation	Yes	No	No	No

As nouns, excretion and evacuation are synonyms defined as:

excretion and evacuation: the bodily process of discharging waste matter

Other synonyms of excretion include elimination, excreting, voiding.

excretion (noun)	evacuation (noun)
the bodily process of discharging waste matter	the act of removing the contents of something
waste matter (as urine or sweat but especially feces) discharged from the body	the act of evacuating; leaving a place in an orderly fashion; especially for protection
	the bodily process of discharging waste matter