not know one end (of something) from another(redirected from not know one end of something from another)
not know one end (of something) from another
To have absolutely no knowledge about something. I don't know one end from another when it comes to computers, so you'll have to explain this to me really slowly. What's an attachment again? Jeff wouldn't know one end of a baby from another. Thank goodness Frank is there to help babysit.