scrub vs unimproved

scrub is a noun but unimproved is not a noun.

Word	Noun	Adjective	Verb	Adverb
scrub	Yes	Yes	Yes	No
unimproved	No	Yes	No	No

scrub (noun)	unimproved (noun)
the act of cleaning a surface by rubbing it with a brush and soap and water
dense vegetation consisting of stunted trees or bushes

scrub (adjective)	unimproved (adjective)
(of domestic animals) not selectively bred	not made more desirable or valuable or profitable; especially not made ready for use or marketing
	(of land) not cleared of trees and brush; in the wild or natural state

scrub (verb)	unimproved (verb)
wash thoroughly
clean with hard rubbing
postpone indefinitely or annul something that was scheduled