Derived from the latin Pasbitinus Bluinus Ribbionus, it is a staple of white trash beverage consumption nation wide. As a noun, it is simple, refering to the midly refreshing Pabst Blue Ribbon Beer. As an adjective, it is being used to describe the people, actions and possesions of those who drink it most.
noun-"I drank a 24 pack of PBR and my wife drank my other case so I ran her over with my 1983 GMC 1500"
adjective"that guy who ran over his wife with the pickup truck is pretty PBR"