In cooking, a sauce is liquid, creaming or semi-solid food served on or used in preparing other foods. sauces are not normally consumed by themselves; they add flavor, moisture, and visual appeal to another dish. sauce is a french word taken from the latin salsa, meaning salted. possibly the oldest sauce recorded is garum, the fish sauce used by the ancient romans. sauces need a liquid component, but some sauces may contain more solid elements than liquid.