flower child vs meliorist

flower child and meliorist both are nouns.

Word	Noun	Adjective	Verb	Adverb
flower child	Yes	No	No	No
meliorist	Yes	No	No	No

As nouns, meliorist is a hypernym of flower child; that is, meliorist is a word with a broader meaning than flower child:

flower child: someone who rejects the established culture; advocates extreme liberalism in politics and lifestyle
meliorist: a disputant who advocates reform

Other hypernyms of flower child include crusader, reformer, reformist, social reformer.

flower child (noun)	meliorist (noun)
someone who rejects the established culture; advocates extreme liberalism in politics and lifestyle	a disputant who advocates reform