BM vs excretory product

BM and excretory product both are nouns.

Word	Noun	Adjective	Verb	Adverb
BM	Yes	No	No	No
excretory product	Yes	No	No	No

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

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

Other hypernyms of BM include body waste, excrement, excreta, excretion.

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