faeces vs muck

faeces and muck both are nouns.

Word	Noun	Adjective	Verb	Adverb
faeces	Yes	No	No	No
muck	Yes	No	Yes	No

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

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

faeces (noun)	muck (noun)
solid excretory product evacuated from the bowels	any thick, viscous matter
	fecal matter of animals

faeces (verb)	muck (verb)
	remove muck, clear away muck, as in a mine
	soil with mud, muck, or mire
	spread manure, as for fertilization