A bunghole is a hole bored in a liquid-tight barrel. The hole is capped with a large cork-like object called a bung.

Bungholes were first used on wooden barrels, and were typically bored by the purchaser of the barrel using a brace and bit . Bungholes can be bored in either head (end) of a barrel or in one of the staves (side). With the bung removed, a tapered faucet can be attached to aid with dispensing. When barrels full of a commodity were shipped, the recipient would often bore new bungholes of the most suitable size and placement rather than remove the existing bung. Wooden barrels manufactured by specialty firms today usually are bored by the maker with suitable bungholes, since the hobbyists who purchase them for the making of beer, wine, and fermented foods often do not have a suitable brace and bit.

Closed-head steel barrels and drums now used for shipment of chemicals and petroleum products have a standardized bunghole arrangement, with one 2" NPT and one 3/4" NPT threaded bunghole on opposite sides of the top head. Some steel barrels are also equipped with a 2" threaded bunghole.

In his (arguably) most famous work, Hamlet, William Shakespeare makes a passing reference to bungholes, as Hamlet contemplates the skull of his old friend Yorick, and how even such high mortals as Alexander the Great must inevitably return to lowly dust:

Hamlet: To what base uses we may return, Horatio! Why may not imagination trace the noble dust of Alexander, till he find it stopping a bung-hole?

Horatio: 'Twere to consider too curiously, to consider so.

Hamlet: No, faith, not a jot; but to follow him thither with modesty enough, and likelihood to lead it: as thus: Alexander died, Alexander was buried, Alexander returneth into dust; the dust is earth; of earth we make loam; and why of that loam, whereto he was converted, might they not stop a beer-barrel?

The terms bung and bunghole have also been used as slang for anus as early as the 13th century. A translation of Dante's Inferno to English from the original Italian uses the term bung when describing the grotesque appearance of a particular sinner who has been split from head to crotch, with his bowels trailing behind him:

Between his legs all of his red guts hung with the heart, the lungs, the liver, the gall bladder, and the shriveled sac that passes shit to the bung.

More recently, this slang use was spoken by President Lyndon Johnson during an inadvertently taped phone call in 1964 in which he orders some pants. [1] But the best-known modern use of the slang term (in the United States, at least) is by Beavis of Beavis and Butt-head. The actual definition of the term was given in one episode of Beavis and Butt-head when two Border Patrol officers hopelessly consulted a dictionary after being unable to understand an over-sugared Beavis in his ranting Cornholio persona.