1. To charge a serving government official with serious misconduct while in office.
2. To remove someone; such as, a President or a judge from public office because of having committed serious crimes and misdemeanors or because of other gross misconduct.
3. To charge someone with a crime or misdemeanor.
4. To question a person's good character.
5. United Kingdom law: to accuse someone of a crime; especially, treason or another crime against the state.
6. Etymology: "to impede, hinder, prevent", from Anglo-French empecher, from Old French empeechier, "hinder" (12th century), from Late Latin impedicare, "to fetter, catch, entangle", from Latin in-, "in" plus pedica, "shackle", from pes (pedis), "foot".

The sense of "accuse a public officer of misconduct" was first recorded in 1568, because of confusion with Latin impetere, "to attack, to accuse".