ungraded vs dirt

ungraded is not a noun while dirt is a noun.

Word	Noun	Adjective	Verb	Adverb
ungraded	No	Yes	No	No
dirt	Yes	Yes	No	No

As adjectives, ungraded and dirt are synonyms defined as:

ungraded and dirt: (of roads) not leveled or drained; unsuitable for all year travel

ungraded (noun)	dirt (noun)
	disgraceful gossip about the private lives of other people
	anything regarded as making something unclean
	the part of the earth's surface consisting of humus and disintegrated rock
	obscene terms for feces

ungraded (adjective)	dirt (adjective)
not arranged in order hierarchically	(of roads) not leveled or drained; unsuitable for all year travel
(of roads) not leveled or drained; unsuitable for all year travel