In the 1960s, the Rat Pack created their own language. It was a mixture of slang and cool terms that helped make them undisputably the 'kings of cool' in this the heyday of Vegas.

In the early 1950s, Frank Sinatra and his crew had been a part of the Holmby Hills Rat Pack, a Hollywood drinking group that gathered around Humphrey Bogart and Lauren Bacall (it also included Judy Garland, Sid Luft, Swifty Lazar, Jimmy Van Heusen, David Niven and Kay Thompson). When Bogart died in 1957, Sinatra took over. Most of the original members quit and the new group formed around Frank's friends, Dean Martin, Joey Bishop, and Sammy Davis, Jr. Peter Lawford joined later. On the fringes of the central group were others like Shirley McLaine, Angie Dickinson, Juliet Prowse, Tony Curtis and Janet Leigh (the women were never official members of the Ratpack).