pitchman vs chapman

pitchman and chapman both are nouns.

Word	Noun	Adjective	Verb	Adverb
pitchman	Yes	No	No	No
chapman	Yes	No	No	No

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

pitchman: someone who travels about selling his wares (as on the streets or at carnivals)
chapman: archaic term for an itinerant peddler

Other hyponyms of pitchman include cheapjack, crier, muffin man, sandboy, transmigrante.

pitchman (noun)	chapman (noun)
someone who travels about selling his wares (as on the streets or at carnivals)	archaic term for an itinerant peddler
an aggressive salesman who uses a fast line of talk to sell something