somebody can do something in their sleepGOOD AT informal used to say that someone is able to do something very easily, especially because they have done it many times before 某人闭上眼睛都能做某事〔尤因已做过多次〕 She knew the music so well she could play it in her sleep. 她对这首乐曲太熟悉了,闭上眼睛也能奏出来。
→ somebody can do something in their sleep at sleep2(4)