fraternity vs social club

fraternity and social club both are nouns.

Word	Noun	Adjective	Verb	Adverb
fraternity	Yes	No	No	No
social club	Yes	No	No	No

As nouns, social club is a hypernym of fraternity; that is, social club is a word with a broader meaning than fraternity:

Other hypernyms of fraternity include club, gild, guild, lodge, order, society.

fraternity (noun)	social club (noun)
people engaged in a particular occupation	a formal association of people with similar interests
a social club for male undergraduates