Underberg is a German herbal digestive liqueur that is known for its strong, bitter flavor and medicinal properties. There are various synonyms used to describe Underberg, including digestive bitters, aperitif, stomach tonic, and herbal elixir. Other terms commonly used are bitter liqueur, bitter herbs, and medicinal herbal liqueur. Because of its beneficial properties, Underberg is often referred to as a herbal remedy that aids digestion and helps treat headaches, nausea, and other stomach problems. Some people also describe Underberg as a digestif, an after-dinner drink that is meant to soothe the stomach and aid digestion.