cloud-covered vs overcast

cloud-covered is not a noun while overcast is a noun.

Word	Noun	Adjective	Verb	Adverb
cloud-covered	No	Yes	No	No
overcast	Yes	Yes	Yes	No

As adjectives, cloud-covered and overcast are synonyms defined as:

Other synonyms of cloud-covered include clouded, sunless.

cloud-covered (noun)	overcast (noun)
	a cast that falls beyond the intended spot
	a long whipstitch or overhand stitch overlying an edge to prevent raveling
	the state of the sky when it is covered by clouds
	gloomy semidarkness caused by cloud cover

cloud-covered (adjective)	overcast (adjective)
filled or abounding with clouds	filled or abounding with clouds

cloud-covered (verb)	overcast (verb)
	sew with an overcast stitch from one section to the next
	sew over the edge of with long slanting wide stitches
	make overcast or cloudy