Fig. to take control of someone; to assume the responsibility of guiding someone. Someone is going to have to take Tim in hand and help him out. Alice decided that she would take the new worker in hand.
Deal with, assume control of, as in He's going to take their debts in hand and see if they need to declare bankruptcy, or Once the new teacher takes them in hand this class will do much better. [c. 1300] Also see in hand, def. 2.