A jug is a type of container commonly used to hold liquid. It has an opening, often narrow, from which to pour or drink, and often has a handle. Most jugs throughout history have been made of ceramic, glass or plastic. Some Native American and other tribes created liquid holding vessels by making woven baskets lined with an asphaltum sealer.
In American English usage, a jug is a large container with a narrow mouth and handle for liquids, and may be used to describe thin plastic sealed shop packaging for milk and other liquids. In all other English speaking countries a jug is any container with a handle and a mouth and spout for liquid, and not used for retail packaging. In American English "pitcher" is the usual word for wide-mouthed vessels, but all other English speaking countries these are called "jugs".
The word jug is first recorded in the late 15th century as jugge or jubbe. It is of unknown origin, but perhaps comes from jug a familiar name used to describe "a low woman, a maidservant" in the same period. This in turn comes from the alteration of common personal names such as Joan or Judith.
In certain countries, especially New Zealand and Australia, a "jug" refers to a jug (usually plastic) containing 2 pints (just over a litre) of beer. It is usually served along with one or more small glasses from which the beer is normally consumed, although in some student bars it is more common for the beer to be drunk directly from the jug, which is usually served without the accompanying glass. (In the U.S., this may be called a pitcher—although few US pitchers are as small as a litre, generally holding between 64 and 128 U.S. fluid ounces, approximately 2-4 litres. In New Zealand and Australia a pitcher sometimes can refer to a much larger measure of beer).
In Britain in those parts of the county where there is a choice between a pint (20 fluid ounces) tankard and a strait glass of beer, a tankard may be called a tankard or a "jug". A jug of beer may also refer to a jug containing larger amounts (usually sized in pints), but if a large jug is sold it will be advertised as such in the pub and this helps to reduce confusion.
As a musical instrument
In American folk music, an empty jug (in the American meaning of the word) is sometimes used as a musical instrument, being played with buzzed lips to produce a trombone-like tone. It is often part of a jug band, to which ensemble it lends its name.