guano vs excretion

guano and excretion both are nouns.

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

As nouns, excretion is a hypernym of guano; that is, excretion is a word with a broader meaning than guano:

guano: the excrement of sea birds; used as fertilizer
excretion: waste matter (as urine or sweat but especially feces) discharged from the body

guano (noun)	excretion (noun)
the excrement of sea birds; used as fertilizer	the bodily process of discharging waste matter
	waste matter (as urine or sweat but especially feces) discharged from the body