class-action suit vs lawsuit

class-action suit and lawsuit both are nouns.

Word	Noun	Adjective	Verb	Adverb
class-action suit	Yes	No	No	No
lawsuit	Yes	No	No	No

As nouns, lawsuit is a hypernym of class-action suit; that is, lawsuit is a word with a broader meaning than class-action suit:

class-action suit: a lawsuit brought by a representative member of a large group of people on behalf of all members of the group
lawsuit: a comprehensive term for any proceeding in a court of law whereby an individual seeks a legal remedy

Other hypernyms of class-action suit include case, causa, cause, suit.

class-action suit (noun)	lawsuit (noun)
a lawsuit brought by a representative member of a large group of people on behalf of all members of the group	a comprehensive term for any proceeding in a court of law whereby an individual seeks a legal remedy