cowpuncher vs cowman

cowpuncher and cowman both are nouns.

Word	Noun	Adjective	Verb	Adverb
cowpuncher	Yes	No	No	No
cowman	Yes	No	No	No

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

cowpuncher: a hired hand who tends cattle and performs other duties on horseback
cowman: a male hired hand who tends cattle and performs other duties on horseback

Other hyponyms of cowpuncher include buckaroo, buckeroo, vaquero, cowgirl, gaucho, horse wrangler, wrangler, roper, cattleman, cowboy.

cowpuncher (noun)	cowman (noun)
a hired hand who tends cattle and performs other duties on horseback	a male hired hand who tends cattle and performs other duties on horseback