assassinate vs smirch

assassinate is not a noun while smirch is a noun.

Word	Noun	Adjective	Verb	Adverb
assassinate	No	No	Yes	No
smirch	Yes	No	Yes	No

As verbs, smirch is a hypernym of assassinate; that is, smirch is a word with a broader meaning than assassinate:

assassinate: destroy or damage seriously, as of someone's reputation
smirch: charge falsely or with malicious intent; attack the good name and reputation of someone

Other hypernyms of assassinate include asperse, besmirch, calumniate, defame, denigrate, slander, smear, sully.

assassinate (noun)	smirch (noun)
	an act that brings discredit to the person who does it
	a blemish made by dirt

assassinate (verb)	smirch (verb)
destroy or damage seriously, as of someone's reputation	charge falsely or with malicious intent; attack the good name and reputation of someone
murder; especially of socially prominent persons	smear so as to make dirty or stained