feces vs meconium

feces and meconium both are nouns.

Word	Noun	Adjective	Verb	Adverb
feces	Yes	No	No	No
meconium	Yes	No	No	No

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

feces: solid excretory product evacuated from the bowels
meconium: thick dark green mucoid material that is the first feces of a newborn child

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

feces (noun)	meconium (noun)
solid excretory product evacuated from the bowels	thick dark green mucoid material that is the first feces of a newborn child