gentleman vs man

gentleman and man both are nouns.

Word	Noun	Adjective	Verb	Adverb
gentleman	Yes	No	No	No
man	Yes	No	Yes	No

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

Other hypernyms of gentleman include adult male.

As nouns, gentleman and man are synonyms defined as:

gentleman and man: a manservant who acts as a personal attendant to his employer

Other synonyms of gentleman include gentleman's gentleman, valet, valet de chambre.

gentleman (noun)	man (noun)
a man of refinement	all of the living human inhabitants of the earth
a manservant who acts as a personal attendant to his employer	any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage
	game equipment consisting of an object used in playing certain board games
	an adult person who is male (as opposed to a woman)
	someone who serves in the armed forces; a member of a military force
	the generic use of the word to refer to any human being
	a manservant who acts as a personal attendant to his employer
	an adult male person who has a manly character (virile and courageous competent)
	a male person who plays a significant role (husband or lover or boyfriend) in the life of a particular woman
	a male subordinate

gentleman (verb)	man (verb)
	provide with workers
	take charge of a certain job; occupy a certain work place