muffin man vs hawker

muffin man and hawker both are nouns.

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

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

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

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

muffin man (noun)	hawker (noun)
formerly an itinerant peddler of muffins	someone who travels about selling his wares (as on the streets or at carnivals)
	a person who breeds and trains hawks and who follows the sport of falconry