congressman vs representative

congressman and representative both are nouns.

Word	Noun	Adjective	Verb	Adverb
congressman	Yes	No	No	No
representative	Yes	Yes	No	No

As nouns, representative is a hypernym of congressman; that is, representative is a word with a broader meaning than congressman:

Other hypernyms of congressman include adult female, woman.

congressman (noun)	representative (noun)
a male member of the United States House of Representatives	an item of information that is typical of a class or group
	a person who represents others
	a member of the United States House of Representatives
	an advocate who represents someone else's policy or purpose

congressman (adjective)	representative (adjective)
	standing for something else
	being or characteristic of government by representation in which citizens exercise power through elected officers and representatives
	serving to represent or typify