impeachment vs impeach

impeachment is a noun but impeach is not a noun.

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

impeachment (noun)	impeach (noun)
a formal document charging a public official with misconduct in office

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