body waste vs fecula

body waste and fecula both are nouns.

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

As nouns, fecula is a hyponym of body waste; that is, fecula is a word with a more specific, narrower meaning than body waste:

body waste: waste matter (as urine or sweat but especially feces) discharged from the body
fecula: excreta (especially of insects)

body waste (noun)	fecula (noun)
waste matter (as urine or sweat but especially feces) discharged from the body	excreta (especially of insects)