noun The sauce that Jack-in-the-box put on their burgers starting in the 1980s. It's the color of thousand island dressing. This "secret" was encouraged by Jack as a way to differentiate itself from the other fast food chains.
Um Fernando, a big drop of secret sauce just flew out of your sandwich and landed in your crotch.
A homogeneous mixture of two or more condiments found in the fridge. Any number of condiments may be used, such as ketchup, mustard, BBQ sauce, or soy sauce. Salad dressing may be added as well. Secret sauce is not at all secret, it's just never the same thing twice. It is usually made as a dipping sauce for fruggets.
I was bored with the individual condiments, so I mixed them all together in a big bowl of secret sauce.