1
general::
Phrase(s): *a million miles away
Fig. lost in thought; [of someone] daydreaming and not paying attention. (Only one’s mind is far away. *Typically: be ~; look to be ~; seem ~.) • He was a million miles away during the entire lecture. • Look at her. She is a million miles away, not paying any attention to what she is doing.
McGrawhill's American Idioms And Phrasal Verbs