1
                           general:: 
                            Phrase(s): *what for 
1. Fig. a scolding; a stern lecture. (*Typically: get ~; give someone ~.)  •  Billy’s mother gave him what for because he didn’t get home on time.  •  I will really give you what for if you don’t straighten up. 2. Why?; For what reason?  •  Father: "I want you to clean your room." Child: "What for? It’s clean enough."  •  What did you do that for?
                        
                        
 
                        
                            McGrawhill's American Idioms And Phrasal Verbs
                        
                        
                    
                    
                        2
                           general:: 
                            1. For what purpose or reason, why, as in I know you're going to England, but what for? [Mid-1700s] 2. A punishment or scolding, as in You'll get what for from Mom if she catches you smoking, or The teacher really gave Bud what for. [Colloquial; second half of 1800s]
                        
                        
 
                        
                            American Heritage Idioms