ferret something out
phrasal verb with ferret verb informal uk/ˈfer.ɪt/ us/ˈfer.ət/
搜寻出，搜索出
to find out a piece of information or find someone or something, after looking in many places or asking many questions
[ + question word ] I know his name but I haven't managed to ferret out where he lives. 我知道他的名字，不过我还没有查出他住在哪儿。