To place a prior date on a legal document, statement or check. also called antedate.
                                                            
                                                     
                        
                                                
                        
                        
                            to make effective from an earlier date; to make retroactive.
                                                            
                                                     
                        
                                                
                        
                        
                            to affix a date earlier than the present date; -- sometimes done for fraudulent purposes.  Opposite of postdate.