Ouzo is a Greek anise-flavored liqueur that is widely consumed in Greece. The name dates back to the late 19th century, but is of uncertain origin It is similar to pastis, but a little sweeter and smoother, so that it is pleasant to drink either "straight" or mixed with water.
The history of ouzo is somewhat murky, but some claim it may date back in one form or another to ancient times. Its precursor is tsipouro (or as it is known by Easterners as raki), a drink distilled throughout the Byzantine and later Ottoman Empires, often in those days of quality approaching moonshine (similar liquors in Turkey and many Arab countries still go by that name).