The term SALAD ADDITIVE can be broken down into two crossword solutions: OIL (3 letters) and VINEGAR (7 letters). OIL and VINEGAR are two of the most common salad additives, and are often used together to create a classic vinaigrette. OIL is usually added first, as it helps to emulsify the VINEGAR and other ingredients, while VINEGAR adds a tart flavor to the salad. Both OIL and VINEGAR can also be used to dress salads without any other ingredients.