cowman vs cowboy

cowman and cowboy both are nouns.

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

As nouns, cowman and cowboy are synonyms defined as:

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

Other synonyms of cowman include cattleman.

cowman (noun)	cowboy (noun)
a male hired hand who tends cattle and performs other duties on horseback	someone who is reckless or irresponsible (especially in driving vehicles)
	a performer who gives exhibitions of riding and roping and bulldogging
	a male hired hand who tends cattle and performs other duties on horseback