muffin man vs peddler

muffin man and peddler both are nouns.

Word	Noun	Adjective	Verb	Adverb
muffin man	Yes	No	No	No
peddler	Yes	No	No	No

As nouns, peddler is a hypernym of muffin man; that is, peddler is a word with a broader meaning than muffin man:

muffin man: formerly an itinerant peddler of muffins
peddler: someone who travels about selling his wares (as on the streets or at carnivals)

Other hypernyms of muffin man include hawker, packman, pedlar, pitchman.

muffin man (noun)	peddler (noun)
formerly an itinerant peddler of muffins	someone who travels about selling his wares (as on the streets or at carnivals)
	an unlicensed dealer in illegal drugs