buttock vs excretion

buttock and excretion both are nouns.

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

buttock (noun)	excretion (noun)
either of the two large fleshy masses of muscular tissue that form the human rump	the bodily process of discharging waste matter
	waste matter (as urine or sweat but especially feces) discharged from the body