impeach vs reproach

impeach is not a noun while reproach is a noun.

Word	Noun	Adjective	Verb	Adverb
impeach	No	No	Yes	No
reproach	Yes	No	Yes	No

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

Other hyponyms of impeach include upbraid, arraign, recriminate, charge, file, lodge.

impeach (noun)	reproach (noun)
	a mild rebuke or criticism
	disgrace or shame

impeach (verb)	reproach (verb)
bring an accusation against; level a charge against	express criticism towards
charge (a public official) with an offense or misdemeanor committed while in office
challenge the honesty or veracity of