special sauce

English

Noun

special sauce (usually uncountable, plural special sauces)

1. A basic ingredient in McDonald's Big Mac hamburgers, a sort of Thousand Island dressing (now called Big Mac sauce by the company).
   • 1975, McDonald's Corporation, Big Mac advertising jingle‎^[1]:

     two all-beef patties, special sauce, lettuce, cheese, pickles, onions, on a sesame seed bun

   • 2001 January, Matt Groening, “Parasites Lost”, in Futurama, season 3, episode 4:

     one day you'll be eatin' a fast-food burger.... Ever wonder what makes special sauce so special?

2. Burger sauce.
3. (figurative) Synonym of secret sauce.