on oath

汉语翻译

发誓, 在誓言的约束下
【法】 发誓

例句

All witnesses must remember that they have been placed on oath and must speak the exact truth.所有的证人必须记住一定要保证讲真话，不得有半句谎言。He was on oath to tell all he saw.他已宣誓要把所看到的一切都讲来出。