Queen's evidence

剑桥词典

evidence from someone who has been accused of committing a crime , given against the people who were accused with them, in order to have their own punishment reduced
被控犯人提供的同犯的罪証
也見
King's evidence
state's evidence
 turn Queen's evidence

to give evidence against someone else in this way
供出同案犯的罪証；揭發其他案犯 返回 Queen's evidence