proponent
noun
                                                                                                                            
                                                            pro·po·nent
                    
                                                                                                              
                                                                                                                                  prə-ˈpō-nənt  
                                                                                                                              
            ˈprō-ˌpō-
                                                      
                                                          
                                
              
          
                                                      : one who argues in favor of something : advocate                                      
                
                    
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  Merriam-Webster unabridged




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