(1):
(n.) Hindrance; impediment; obstruction.
(2):
(n.) A calling to account; arraignment; especially, of a public officer for maladministration.
(3):
(n.) The act of impeaching, or the state of being impeached
(4):
(n.) A calling in question as to purity of motives, rectitude of conduct, credibility, etc.; accusation; reproach; as, an impeachment of motives.