scrub vs set back

scrub is a noun but set back is not a noun.

Word	Noun	Adjective	Verb	Adverb
scrub	Yes	Yes	Yes	No
set back	No	No	Yes	No

scrub (noun)	set back (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)	set back (adjective)
(of domestic animals) not selectively bred

scrub (verb)	set back (verb)
wash thoroughly	slow down the progress of; hinder
clean with hard rubbing	cost a certain amount
postpone indefinitely or annul something that was scheduled	hold back to a later time