blue joke vs excretion

blue joke and excretion both are nouns.

Word	Noun	Adjective	Verb	Adverb
blue joke	Yes	No	No	No
excretion	Yes	No	No	No

blue joke (noun)	excretion (noun)
an indelicate joke	the bodily process of discharging waste matter
	waste matter (as urine or sweat but especially feces) discharged from the body