ill-considered vs improvident

ill-considered and improvident both are adjectives.

Word	Noun	Adjective	Verb	Adverb
ill-considered	No	Yes	No	No
improvident	No	Yes	No	No

As adjectives, ill-considered and improvident are synonyms defined as:

Other synonyms of ill-considered include ill-judged, shortsighted.

ill-considered (adjective)	improvident (adjective)
not given careful consideration	not provident; not providing for the future
	not given careful consideration