dirty vs smear

dirty is not a noun while smear is a noun.

Word	Noun	Adjective	Verb	Adverb
dirty	No	Yes	Yes	No
smear	Yes	No	Yes	No

As verbs, smear is a hyponym of dirty; that is, smear is a word with a more specific, narrower meaning than dirty:

Other hyponyms of dirty include foul, contaminate, foul, pollute, slime, muddy, muddy up, splash, mire, muck, muck up, mud, crock, blemish, spot.

dirty (noun)	smear (noun)
	an act that brings discredit to the person who does it
	a blemish made by dirt
	a thin tissue or blood sample spread on a glass slide and stained for cytologic examination and diagnosis under a microscope
	slanderous defamation

dirty (adjective)	smear (adjective)
soiled or likely to soil with dirt or grime
(of behavior or especially language) characterized by obscenity or indecency
spreading pollution or contamination; especially radioactive contamination
unethical or dishonest
expressing or revealing hostility or dislike
obtained illegally or by improper means
(of a manuscript) defaced with changes
(of color) discolored by impurities; not bright and clear
vile; despicable
contaminated with infecting organisms
unpleasantly stormy
violating accepted standards or rules

dirty (verb)	smear (verb)
make soiled, filthy, or dirty	charge falsely or with malicious intent; attack the good name and reputation of someone
	make a smudge on; soil by smudging
	stain by smearing or daubing with a dirty substance
	cover (a surface) by smearing (a substance) over it