excrement vs waste product

excrement and waste product both are nouns.

Word	Noun	Adjective	Verb	Adverb
excrement	Yes	No	No	No
waste product	Yes	No	No	No

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

excrement: waste matter (as urine or sweat but especially feces) discharged from the body
waste product: any materials unused and rejected as worthless or unwanted

Other hypernyms of excrement include waste, waste material, waste matter.

excrement (noun)	waste product (noun)
waste matter (as urine or sweat but especially feces) discharged from the body	any materials unused and rejected as worthless or unwanted