<p><strong>Verb (used with object):</strong></p><ul><li>to accuse (a public official) before an appropriate tribunal of misconduct in office.</li><li>to challenge the credibility of: to impeach a witness.</li><li>to bring an accusation against.</li><li>to call in question; cast an imputation upon: to impeach a person's motives.</li><li>to charge with responsibility for all or part of an undesirable situation, harmful effect, etc.: to incriminate cigarettes as a cause of lung cancer.</li></ul><p><strong>Noun (obsolete):</strong></p><ul><li>impeachment.</li></ul>