cofound
verb
                                                                                                                            
                                                            co·found
                    
                                                                                                              
                                                                                                                                  ˌkō-ˈfau̇nd  
                                                      
                                                          
            
            variants  
 or co-found
        
    
            
              cofounded or co-founded; cofounding or co-founding            
        
    
                                
              
          
                                                      : to join one or more others in founding (something, such as an organization or institution) : to found (something) jointly                                      
              
                             
Renowned prankster and engineer Steve Wozniak has returned to the company he cofounded seven years ago.— Paul Freiberger
Paul Freiberger
                                       … she went on to co-found the Agricultural Workers Association, which would eventually become the United Farm Workers.— Ericka N. Goodman-Hughey
Ericka N. Goodman-Hughey
                         
                
                    
                                                      cofounder
                        
                                      noun
                                                                                                      
                        
                        
      
 or co-founder
                                                                                         plural cofounders or co-founders
                                                            
          
         
                        … Beach Boys' legend and cofounder Brian Wilson performing the entire album "Pet Sounds" is enough to give any summer concertgoer a good vibration.    
        
        
            — Craig S. Semon
Craig S. Semon          
  
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  Merriam-Webster unabridged




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