guano vs excrement

guano and excrement both are nouns.

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

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

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

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