piss vs body waste

piss and body waste both are nouns.

Word	Noun	Adjective	Verb	Adverb
piss	Yes	No	Yes	No
body waste	Yes	No	No	No

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

piss: liquid excretory product
body waste: waste matter (as urine or sweat but especially feces) discharged from the body

Other hypernyms of piss include excrement, excreta, excretion, excretory product.

piss (noun)	body waste (noun)
informal terms for urination	waste matter (as urine or sweat but especially feces) discharged from the body
liquid excretory product

piss (verb)	body waste (verb)
eliminate urine