暗中警告,私下告诫,密报(尤指非法的事情)
tip sb off (about sth)
to warn sb about sth that is going to happen, especially sth illegal
Three men were arrested after police were tipped off about the raid.警方获得有关袭击的密报后,逮捕了三个人。
释义来自《牛津高阶英汉双解词典》第 9 版