/ˈwɪtnəs/ – noun
Definition: 1. nhân chứng, người chứng kiến;
2. chứng cứ, lời khai của nhân chứng, cung cấp lời chứng, làm chứng, chứng nhận, ký tên với tư cách nhân chứng.
A more thorough explanation: A witness is a person who has firsthand knowledge of an event or situation and can provide testimony or evidence about it in a legal proceeding, such as a trial or deposition. Witnesses are typically called upon to provide information that is relevant to the case at hand and may be required to swear an oath to tell the truth before giving their testimony.
Example: The witness testified under oath during the trial.