BM vs body waste

BM and body waste both are nouns.

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

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

BM: solid excretory product evacuated from the bowels
body waste: waste matter (as urine or sweat but especially feces) discharged from the body

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

BM (noun)	body waste (noun)
solid excretory product evacuated from the bowels	waste matter (as urine or sweat but especially feces) discharged from the body