Tzatziki, also known as cacık or tarator, is a class of dip, soup, or sauce found in the cuisines of Southeastern Europe and West Asia. It is made of salted strained yogurt or diluted yogurt mixed with cucumbers, garlic, salt, olive oil, red wine vinegar, sometimes with lemon juice, and herbs such as dill, mint, parsley and thyme. It is served as a cold appetiser (meze), a side dish, and as a sauce for souvlaki and gyros sandwiches and other foods.

A dip or dip sauce is a common condiment for many types of food. Dips are used to add flavor or texture to a food, such as pita bread, dumplings, crackers, chopped raw vegetables, fruits, seafood, cubed pieces of meat and cheese, potato chips, tortilla chips, falafel, and sometimes even whole sandwiches in the case of jus. Unlike other sauces, instead of applying the sauce to the food, the food is typically placed or dipped into the sauce.