smear vs besmirch

smear is a noun but besmirch is not a noun.

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

As verbs, smear and besmirch are synonyms defined as:

smear and besmirch: charge falsely or with malicious intent; attack the good name and reputation of someone

Other synonyms of smear include asperse, calumniate, defame, denigrate, slander, smirch, sully.

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

Other hyponyms of smear include moil, smirch.

smear (noun)	besmirch (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

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