Worcestershire sauce
Worcestershire sauce is a thin, dark, rather piquant sauce used to season meats, soups and vegetable juices, and as a table condiment. It's formula includes garlic, soy sauce, tamarind, onions, molasses, lime, anchovies, vinegar and various seasonings. It was originally developed in India by the English, it takes its name from the fact that it was first bottled in Worcester, England.
At the bar Worcestershire sauce is used as a flavoring agent, and without it drinks like the Bloody Mary would not exist.