ordure vs melaena

ordure and melaena both are nouns.

Word	Noun	Adjective	Verb	Adverb
ordure	Yes	No	No	No
melaena	Yes	No	No	No

As nouns, melaena is a hyponym of ordure; that is, melaena is a word with a more specific, narrower meaning than ordure:

ordure: solid excretory product evacuated from the bowels
melaena: abnormally dark tarry feces containing blood (usually from gastrointestinal bleeding)

Other hyponyms of ordure include dog do, dog shit, dog turd, doggy do, crap, dirt, poop, shit, shite, turd, droppings, dung, muck, meconium, melena.

ordure (noun)	melaena (noun)
solid excretory product evacuated from the bowels	abnormally dark tarry feces containing blood (usually from gastrointestinal bleeding)