Pronunciation: (im-pēch'munt),[key] —n. 1. the impeaching of a public official before an appropriate tribunal.
2. (in Congress or a state legislature) the presentation of formal charges against a public official by the lower house, trial to be before the upper house.
3. demonstration that a witness is less worthy of belief.
4. the act of impeaching.
5. the state of being impeached.