Gab is a slang term that means idle chatter, or chit-chat. On January 18, 1927, Marty McFly took the alias of "Zipper" McFly, and Emmett Brown convinced "Mugsy" Tannen that Zipper was the head of a mob family from the east coast of the United States. When they met Tannen's boss, Arnie "Eggs" Benedict, he told Marty and Doc to meet him at speakeasy, where they'll gab about the trouble the Bendict mob had been having with a rival mob.