unrehearsed
adjective
                                                                                                                            
                                                            un·re·hearsed
                    
                                                                                                              
                                                                                                                                  ˌən-ri-ˈhərst 
                                                      
                                                          
            
                                
              
          
                                                      : not practiced or prepared : not rehearsed : spontaneous                                      
              
                             
an honest and unrehearsed response
                                       a performance that was largely unrehearsed
                         
                
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  Merriam-Webster unabridged




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