well-off vs prosperous

well-off and prosperous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
well-off	No	Yes	No	No
prosperous	No	Yes	No	No

As adjectives, well-off and prosperous are synonyms defined as:

well-off and prosperous: in fortunate circumstances financially; moderately rich

Other synonyms of well-off include comfortable, easy, well-fixed, well-heeled, well-situated, well-to-do.

well-off (adjective)	prosperous (adjective)
fortunately situated	marked by peace and prosperity
in fortunate circumstances financially; moderately rich	presaging or likely to bring good luck or a good outcome
	in fortunate circumstances financially; moderately rich
	very lively and profitable