well-to-do vs prosperous

well-to-do and prosperous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
well-to-do	No	Yes	No	No
prosperous	No	Yes	No	No

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

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

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

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