businessmen vs profession

businessmen and profession both are nouns.

Word	Noun	Adjective	Verb	Adverb
businessmen	Yes	No	No	No
profession	Yes	No	No	No

As nouns, profession is a hypernym of businessmen; that is, profession is a word with a broader meaning than businessmen:

businessmen (noun)	profession (noun)
the body of individuals who manage businesses	an occupation requiring special education (especially in the liberal arts or sciences)
	an open avowal (true or false) of some belief or opinion
	affirmation of acceptance of some religion or faith
	the body of people in a learned occupation