N-COUNT A witness to an event such as an accident or crime is a person who saw it.目击者 V-T If you witness something, you see it happen.目击
N-COUNT A witness is someone who appears in a court of law to say what they know about a crime or other event.证人
N-COUNT A witness is someone who writes their name on a document that you have signed, to confirm that it really is your signature.连署人
V-T If someone witnesses your signature on a document, they write their name after it, to confirm that it really is your signature.连署
V-T If you say that a place, period of time, or person witnessed a particular event or change, you mean that it happened in that place, during that period of time, or while that person was alive.见证