A person who saw or heard an event and can give an account of it in court or to investigators; a witness.
事故の証人として警察に事情を話した。
I told the police what happened as a witness to the accident.
目撃者の証言は事件解決の手がかりになった。
The witness's testimony became a clue to solving the case.
弁護士は複数の証人を呼んだ。
The lawyer called multiple witnesses.