Pronunciation: (im-pēch'),[key] —v.t. 1. to accuse (a public official) before an appropriate tribunal of misconduct in office.
2. Chiefly Law.to challenge the credibility of: to impeach a witness. 3. to bring an accusation against.
4. to call in question; cast an imputation upon: to impeach a person's motives. 5. to call to account.