mud vs mud pie

mud and mud pie both are nouns.

Word	Noun	Adjective	Verb	Adverb
mud	Yes	No	Yes	No
mud pie	Yes	No	No	No

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

Other hyponyms of mud include bleaching clay, bleaching earth, mire, slop.

mud (noun)	mud pie (noun)
slanderous remarks or charges	a mass of mud that a child has molded into the shape of pie
water soaked soil; soft wet earth

mud (verb)	mud pie (verb)
soil with mud, muck, or mire
plaster with mud