/ɪmˈpiːtʃt ˈwɪtnəs/ – Phrase
Definition: 1. nhân chứng không được chấp nhận;
2. chứng cứ không được chấp nhận.
A more thorough explanation: An impeached witness is a witness whose credibility or truthfulness has been called into question during legal proceedings, typically through evidence or testimony that undermines their reliability as a witness. This may result in their testimony being given less weight or being disregarded altogether by the trier of fact.
Example: The defense attorney cross-examined the impeached witness to challenge the credibility of their testimony.