muck vs cow pie

muck and cow pie both are nouns.

Word	Noun	Adjective	Verb	Adverb
muck	Yes	No	Yes	No
cow pie	Yes	No	No	No

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

Other hyponyms of muck include buffalo chip, chip, cow chip, cow dung, coprolite, pigeon droppings, cowpie.

muck (noun)	cow pie (noun)
any thick, viscous matter	fecal matter of a cow
fecal matter of animals

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